Western Atlas Log Interpretation Charts

Log Interpretation Charts

ATLAS

Atlas Wireline Services

1

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-III

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Log Interpretation Charts

f

WESTERN

ATLAS

Atlas Wireline Services

1

© Copyright 1985 All rights reserved. Alias Wireline Services

Western Atlas International, Inc.

10205 Westheimer Road Houston, Texas 77042-3192 Tel 713-972-4000 Fax 713-972-5298

Telex 6717084 WAI AWS

Printed in the U.S.A. This book, or parts thereof, may not be reproduced in any fonn without permission of the copyright holder.

The data and charts contained herein were obtained from reliable sources and are believed to be accurate. However, we cannot guarantee the absolute accuracy of these data and charts, and readers must use their own judgment in using this material to plan their operations.

AT93-I92

1901

Rev. 7/94

5M

IPP

Foreword

This edition of the Atlas Wireline Services Log Interpretation Charts contains major updates and revi sions. Some charts deleted from previous editions of this text have been reinstated. Other charts have been revised because of new laboratory measurements or computer-generated data.

The opening section of this edition is devoted to general information and contains charts, nomograms, and tables often useful in log analysis. For example, a list of service mnemonics for Atlas Wireline is given. A chart suggesting the proper mud excluder to be used with the Circumferential Borehole Imaging Log (CBIL™) tool in different sizes of boreholes has been included. The different log scales and depth scales are described and graphically presented. An explanation of time markers and their

relation to logging speed is also presented. A brief explanation of the acoustic waveform is given. Symbols used on well logs and most of the common map symbols have also been added to this sec tion. A geologic time table is provided and several common geologic terms are described graphically. The comparative links between log responses and geological facies is presented in a table. Curve

shape characteristics with relation to particular depositional environments and some core analysis ter minology are also presented.

Numerous new charts have been added throughout this edition, particularly in the resistivity section, including a chart that can be used to select the proper deep-resistivity tool for the logging environment. Spectralog® charts for estimating feldspars or micas and two clay types have also been added. A major effort was made to correct minor discrepancies and to add more convenience in scaling; i.e., English and metric terms. Charts for obtaining formation strength parameters have been reinstated. The chart for pipe expansion due to internal pressure contains additional interpretative lines for larger casings, and the cement evaluation charts have been updated along with a form for information on cement jobs.

Supplemental charts include diffusion correction charts for the PDK-100® instrument, two examples of the extensive set (>I,000) of interpretation charts for Magnelog data, one example [15.5 Ib/ft (23.1 kg/m) J-55] of the Vfertilog® interpretation charts, and a chart for the short-spaced dielectric tool. A chart to estimate gas density at reservoir conditions and suggested relations of hydrocarbon density to particular hydrocarbon types has also been added.

Fora more in-depth treatment of certain log analysis-related topics, the Atlas Wireline Services text

entitled. Introduction to Wireline Log Analysis is suggested reading.

in

Contents Section

Chart

Page

Foreword

1 General Information Formation Parameters

.1-1

. .1

Conventional Symbols for Well Logging and Formation Evaluation

.1-2

. .2

Conventional Subscripts for Well Logging and Formation Evaluation

.1-3

..3

Unit Conversions

.1-4.

..5

-5

,J

Service Mnemonics - Products Category Listing

1-6

..8

Service Mnemonics - Products Alphabetical Listing

1-7

Description of Core Analysis

Common Log Presentation Formats

.10 .11

Well Log Scales

-9.

.12

BHC Acoustilog Presentation

-10

.13

Symbols Used on Well Logs

-11

.14

Map Symbols for Identifying Well Conditions

-12

.15

Paleofacies Characteristics

-13

.16

Grain Size Scales for Sediments

-14

.17

Comparison Chart for Sorting and Sorting Classes

•15

.18

■16

.19

■17

.20

■18

.21

■19

.22

Curve Shape Characteristics

.

Time Rock Correlation

,

Generalized Table of Geologic Time and Occurrences of Major Tectonic, Climatic, and Paleontological Event

Circumferential Borehole Imaging Log (CBIL) Operating Range and Mud Excluder Selection

L Temperature and Fluids Estimation of Formation Temperature

.2-1

.23

Estimation of Rmf and Rmc

.2-2

.24

Determination of Static Bottomholc Formation Temperature

.2-3

.25

Equivalent NaCl Concentrations from Total Solids Concentrations

.2-4

.26

Resistivity of Equivalent NaCl Solutions

.2-5

.27

Total Salinity Versus Density of Different Solutions

.2-6

.28

.2-7

.29

.2-8

.30

.2-9

.31

SP Bed Thickness Correction

.3-1

.33

R weqq

.3-2

.34

f Rw from Rweq as a Function of Temperature (*F)

.3-3

.35

Rw from Rweq as a Function of Temperature (*C)

.3-4

.36

Gamma Ray Borehole Size and Mud Weight Correction for 1-11/16-in. Diameter Instrument .

.4-1 .

.37

Gamma Ray Borehole Size and Mud Weight Correction for 43-mm Diameter Instrument

.4-2.

.38

Gamma Ray Borehole Size and Mud Weight Correction for 3-5/8-in. Diameter Instrument ...

.4-3.

.39

Gamma Ray Borehole Size and Mud Weight Correction for 92-mm Diameter Instrument ....

.4-4.

.40

Spectralog Total Gamma Ray Response-Borehole Size and Mud Weight Correction (English)

.4-5.

.41

Spectralog Total Gamma Ray Response-Borehole Size and Mud Weight Correction (Metric) .

.4-6.

.42

Spectralog Uranium Response-Borehole Size and Mud Weight Correction (English)

.4-7.

.43

Spectralog Uranium Response-Borehole Size and Mud Weight Correction (Metric)

.4-8.

.44

Spectralog Potassium Response-Borehole Size and Mud Weight Correction (English)

.4-9.

.45

Spectralog Potassium Response-Borehole Size and Mud Weight Correction (Metric)

.4-10

.46

Variation of Brine Density with Temperature and Pressure

Comparison of Temperature Gradient Steepness and Lithology

,

Brine Density as a Function of Fluid Salinity and Formation Temperature and Pressure

J Spontaneous Potential

*-f Natural Radioactivity

Contents

Section

Chart

Page

Speclralog Thorium Response-Borehole Size and Mud Weight Correction (English)

4-11

47

Spectralog Thorium Response-Borehole Size and Mud Weight Correction (Metric)

4-12

48

Gamma Ray Correction for KC1 Mud - 3-5/8-in. Diameter Instrument (Decentralized) (English)

4-13

49

Gamma Ray Correction for KC1 Mud - 92-mm Diameter Instrument (Decentralized) (Metric)

4-14

50

Spectralog Total Gamma Ray Correction for KCI Mud (English)

4-15

51

Spectralog Total Gamma Ray Correction for KCI Mud (Metric)

4-16

52

Spectralog Potassium Correction for KCI Mud (English)

4-17

53

Spectralog Potassium Correction for KCI Mud (Metric)

4-18

54

Shale Volume from Radioactivity Index

4-19

55

An Interpretative Model for Spectral Gamma Ray Mineral Identification

4-20

56

Spectralog Mineral Estimates

4-21

57

J Microresistivity Rxo from Micro Laterolog

5-1

59

Borehole Size Correction for Micro Laterolog (Series 1233, 1236.3140) K = 0.01439

5-2

60 61

Minilog and Rxo Determination of Porosity and Formation Factor

5-3

Simplified Minilog Porosity Determination

5-4

62

Borehole Size Correction for Thin-Bed Resistivity Tool (TBRT) (Series 1236 XB K = 0.0052)

5-5

63

O Porosity and Lithology Conductivity-Derived, Water-Filled Porosity

6-1

65

Density Porosity and Shaliness Correction for Constant pf and Varying pf

6-2

66

Porosity and Gas Saturation in Empty Boreholes - Density and 6-3

67

Acoustic Porosity and Shaliness Correction for Constant Atrand Varying Atf (English)

Hydrogen Index of the Gas Assumed to be Zero

6-4

68

Acoustic Porosity and Shaliness Correction for Constant Atf and Varying Atf (Metric)

6-5

69

Acoustic Porosity Determination (Clean Formations)

6-6

70

Pe Borehole Size Correction in Air and Water (for Compensated Z-Densilog - Series 2222)

6-7

72

Pe Borehole Size Correction in Water-Based Barite Mud

6-8

73

Bulk Density Borehole Size Correction (for Compensated Z-Densilog - Series 2222)

(for Compensated Z-Densilog - Series 2222)

6-9

74

Bulk Density Borehole Size Correction (for Compensated Densilog - Series 2227)

6-10

75

Compensated Neutron Borehole Size Correction (for Series 2418 CN Log)

6-11

76

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log) (0 ppm NaCI)

6-12

77

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log) (50 kppm NaCI)

6-13

78

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log) (100 kppm NaCI)

6-14

79

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log) (150 kppm NaCI)

6-15

80

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log) (200 kppm NaCI)

6-16

81

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log) (250 kppm NaCI)

6-17

82

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log) (0 ppm NaCI)

6-18

83

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log) (50 kppm NaCI)

6-19

84

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log) (100 kppm NaCI)... .6-20

85

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log) (150 kppm NaCI)

6-21

86

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log) (200 kppm NaCI)

6-22

87

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log) (250 kppm NaCI)

6-23

88

Sidewall Neutron Mudcake Correction

6-24

89

Compensated Neutron Mudcake, Casing, and Cement Correction (for Series 2420 CN Log)

6-25

90

Formation Salinity and Mud Weight Correction (for Series 2420 CN Log)

6-26

91

Compensated Neutron Mud Weight Correction (for Series 2435 CN Log) (Freshwater Barite Muds)

6-27

92

Compensated Neutron Mud Weight Correction (for Series 2435 CN Log) (Freshwater Non-Barite Muds) ... .6-28

93

Compensated Neutron Standoff Correction (for Series 2418 CN Log)

6-29

94

Compensated Neutron Standoff Correction (for Series 2420 CN Log)

6-30

95

VI

Contents Section

Chart

Page

Compensated Neutron Standoff Correction (for Series 2435 CN Log)

6-31

96

Compensated Neutron Log Temperature and Pressure Correction

6-32

97

Compensated Neutron Combined Lithology and Absorber Effect

6-33

98

Mudcake Correction for Compensated Neutron Log

6-34

99

Mud Weight Correction for Compensated Neutron Log

6-35

100

Compensated Neutron Lithology Effect (for Series 2420 CN Log and Sidewall Neutron)

6-36

101

Compensated Neutron Lithology Effect (for Series 2435 CN Log)

6-37

102

Compensated Neutron Log and Sidewall Neutron Log: Lithology and Shaliness-Corrected Porosity

6-38

103

Formation Salinity Effect (for Series 2435 CN Log)

6-39

104

6-40

105

6-41

106

6-42

107

Porosity and Lithology Determination from Compensated Density and Compensated Neutron Log (for Series 2420 CN Log) Porosity and Lithology Determination from Compensated Density and Compensated Neutron Log

(for Series 2420 CN Log) Porosity and Lithology Determination from Compensated Density and Compensated Neutron Log (for Series 2435 CN Log)

Porosity and Lithology Determination from Compensated Density and Compensated Neutron Log 6-43

108

Porosity and Ltthology Determination from Compensated Density and Sidewall Neutron Log

(for Series 2435 CN Log)

6-44

109

Porosity and Lithology Determination from Compensated Density and Sidewall Neutron Log

6-45

110

6-46

Ill

6-47

112

6-48

113

Porosity and Lithology Determination from Compensated Neutron Log and BHC Acoustilog

(for Series 2420 CN Log)

Porosity and Lithology Determination from Compensated Neutron Log and BHC Acoustilog) (for Series 2420 CN Log) Porosity and Lithology Determination from BHC Acoustilog and Compensated Neutron Log

(for Series 2435 CN Log) Porosity and Lilhology Determination from BHC Acoustilog and Compensated Neutron Log

6-49

114

Porosity and Lithology Determination from Sidewall Neutron Log and BHC Acoustilog

(for Series 2435 CN Log)

6-50

115

Porosity and Lithology Determination from Sidewall Neutron Log and BHC Acoustilog

6-51

116

Porosity and Lithology Determination from Compensated Density and BHC Acoustilog

6-52

117

Porosity vs. Formation Factor

6-53

118

Mineral Identification by M-N Crossplot (using Scries 2420 CN Log)

6-54

119

Mineral Identification by M-N Crossplot (using Series 2435 CN Log)

6-55

120

Mineral Identification by M-N Crossplot (Sidewall Neutron Log)

6-56

121

Mineral Identification Plot - pmaa vs. Atmaa

6-57

122

Porosity and Lithology Determination from Compensated Z-Densilog (pj- = 1.0 g/cm3 or Mg/m3) Porosity and Lithology Determination from Compensated Z-Densilog (pf = 1.1 g/cm3 or Mg/m3)

6-58 6-59

123 124

Matrix Identification Plot

6-60

1 *>5

Porosity Correction for Gypsum Infilling

6-61

126

Estimation of Porosity in Hydrocarbon-Bearing Formations

6-62

127

Estimation of Hydrocarbon Density in Clean Formation

6-63

128

Estimation of Gas Density at Reservoir Conditions

6-64

129

Induction or Laterolog — Deciding Which Tool Should be the Most Effective and Reliable

7-1

131

Borehole Size Correction (for Series 811 Induction Log) Borehole Size Correction (for Series 811 Induction Log)

7-2 7.3

132 133

/ Resistivity and Water Saturation

Borehole Size Correction (for Scries 814 Induction Log)

7.4

134

Borehole Size Correction (for Series 814 Induction Log)

7.5

135

Borehole Size Correction (for Series 815-818-809 Induction Log)

7.6

136

Borehole Size Correction (for Series 815-818-809 Induction Log)

7.7

137

Borehole Size Correction for Deep Induction Log (for Series 1503/1507 DIFL/DPIL)

7-8

138

VII

Contents Section

Chart

Page

Borehole Size Correction for Deep Induction Log (for Series 1503/1507 DIFL/DPIL)

7-9

139

Borehole Size Correction for Medium Induction Log (for Series 1503/1507 DIFL/DPIL)

7-10

140

Borehole Size Correction for Medium Induction Log

7-11

|4|

Bed Thickness Correction for Deep Induction Log

7-12

142

Bed Thickness Correction for Deep Induction Log

7-13

143

Bed Thickness Correction for Dual Laterolog

7-14

144

7-15

145

7-16

146

7-17

147

7-18

148

7-19

149

7-20

150

7-21

151

7-22

152

7-23

153

7-24

154

7-25

155

7-26

156

7-27

157

7-28

158

7-29

159

7-30

160

7-31

161

7-32

162

7-33

163

7-34

164

7-35

165

7-36

166

7-37

167

Borehole Size Correction for Dual Laterolog (DLL) Deep

(for Series 1229 EA/EB Centered, K = 0.7998) Borehole Size Correction for Dual Laterolog (DLL) Deep (for Series 1229 EA/EB Eccentered, K = 0.7998) Borehole Size Correction for Dual Laterolog (DLL) Deep

(for Series 1229 EA/EB Pipe Conveyed, K = 0.7998) Borehole Size Correction for Dual Laterolog (DLL) Shallow (for Series 1229 EA/EB Centered, K = 1.3379) Borehole Size Correction for Dual Laterolog (DLL) Shallow (for Series 1229 EA/EB Eccentered, K = 1.3379) Borehole Size Correction for Dual Laterolog (DLL) Shallow

(for Series 1229 EA/EB Pipe Conveyed. K = 1.3379) Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EA/EB Centered, K = 0.9029) Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EA/EB Eccentered, K = 0.9029)

Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EA/EB Pipe Conveyed. K = 0.9029) Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EA/EB Centered, K = 0.8765) Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EA/EB Eccentered, K = 0.8765) Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EA/EB Pipe Conveyed. K = 0.8765) Borehole Size Correction for Dual Laterolog (DLL) Deep

(for Series 1229 EC Centered, K = 0.7939) Borehole Size Correction for Dual Laterolog (DLL) Deep

(for Series 1229 EC Eccentered, K = 0.7939) Borehole Size Correction for Dual Laterolog (DLL) Deep

(for Series 1229 EC Pipe Conveyed, K = 0.7939) Borehole Size Correction for Dual Laterolog (DLL) Shallow

(for Series 1229 EC Centered, K = 0.9821) Borehole Size Correction for Dual Laterolog (DLL) Shallow

(for Series 1229 EC Eccentered, K = 0.9821) Borehole Size Correction for Dual Laterolog (DLL) Shallow

(for Series 1229 EC Pipe Conveyed, K = 0.9821) Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EC Centered, K = 0.8984) Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EC Pipe Conveyed, K = 0.8984) Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EC Ecccntered. K = 0.8984) Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EC Centered, K = 0.8712) Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EC Eccentered, K = 0.8712)

VIII

Contents Section

Chart

Page

Borehole Size Correction for Dual Laterolog (DLL) Groningen

(for Series 1229 EC Pipe Conveyed. K = 0.8712)

7-38

168

7-39

169

7-40

170

7-41

171

7-42

172

7-43

173

7-44

174

7-45

175

7-46

176

7-47

177

7-48

178

7-49

|79

7-50

180

7-51

181

7-52

|82

7.53

183

7.54

184

7.55

|85

7.56

|86

7.57

\$-j

7.58

| Rg

7.59

189

7-60

)9q

7.6I

191

7_62

192

7.63

j 93

7-64

194

Borehole Size Correction for Dual-Phase Induction (DPIL) - Shallow Focused Log (for Series 1507 XB Centered. K = 2.13) Borehole Size Correction for Dual-Phase Induction (DPIL) - Shallow Focused Log

(for Series 1507 XB Eccentered. K = 2.13) Borehole Size Correction for Dual-Induction Focused Log (DIFL) (for Series 1503 XC Centered. K = 0.7807) Borehole Size Correction for Dual-Induction Focused Log (DIFL) (for Scries 1503 XC Eccentered. K =0.7807)

R, from 1229 EA/EB Dual Laterolog (for R, > Rxo) Using Deep (Rlld>- Shallow (RLLS). and Rxo

R, from 1229 EA/EB Dual Laterolog (for R, > Rxo) Using Groningen (Rllg>- Snallow C^LLS*and Rxo. Current Return at 40 ft

R, from 1229 EA/EB Dual Laterolog (for R, > Rxo) Using Groningen (RLLG), Shallow (Rib and Rxo. Current Return at 60 ft

Rt from 1229 EC Dual Laterolog (for Rt > Rxo) Using Deep (Rjxd)- Shallow (Rjxs). and Rxo

Rt from 1229 EC Dual Laterolog (for Rt > Rxo) Using Groningen (Rllg>- Shallow (R|xs). and Rxo. Current Return at 40 ft

R, from 1229 EC Dual Laterolog (for R, > Rxo) Using Groningen (RLlg>- Shallow
R, from 1507 XB (for Rxo > Rt), Dual-Phase Induction Log (DPIL) (10 kHz, Rxo = I ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > Rt). Dual-Phase Induction Log (DPIL) (20 kHz. Rxo = I ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > R,), Dual-Phase Induction Log (DPIL) (40 kHz. Rxo = I ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > Rt). Dual-Phase Induction Log (DPIL) (10 kHz. Rxo = 10 ohm-m) Shallow Focused Log (SFL)

Rt from 1507 XB (for Rxo > R,), Dual-Phase Induction Log (DPIL) (20 kHz, Rxo = 10 ohm-m) Shallow Focused Log (SFL)

Rt from 1507 XB (for Rxo > R,). Dual-Phase Induction Log (DPIL) (40 kHz. Rxo = 10 ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > R,). Dual-Phase Induction Log (DPIL) (10 kHz. Rxo = 20 ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > R,), Dual-Phase Induction Log (DPIL) (20 kHz, Rx0 = 20 ohm-m) Shallow Focused Log (SFL) R, from 1507 XB (for Rxo > Rt), Dual-Phase Induction Log (DPIL) (40 kHz, Rxo = 20 ohm-m) Shallow Focused Log (SFL)

Rt from 1507 XB (for Rxo > R,), Dual-Phase Induction Log (DPIL) (10 kHz, Rxo = 50 ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > R,), Dual-Phase Induction Log (DPIL) (20 kHz, Rxo = 50 ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > R,), Dual-Phase Induction Log (DPIL) (40 kHz. Rxo = 50 ohm-m) Shallow Focused Log (SFL)

Rt from 1507 XB (for Rxo > R,). Dual-Phase Induction Log (DPIL) (10 kHz. Rxo = 100 ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > R,), Dual-Phase Induction Log (DPIL) (20 kHz. Rxo = 100 ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo > Rt). Dual-Phase Induction Log (DPIL) (40 kHz. Rxo = 100 ohm-m) Shallow Focused Log (SFL)

R, from 1507 XB (for Rxo < Rt), Dual-Phase Induction Log (DPIL) (10 kHz, Rxo = 1 ohm-m) Shallow Focused Log (SFL)

IX

Contents

Section

Chart

Page

Rt from 1507 XB (for Rxo < R,), Dual-Phase Induction Log (DPIL) (20 kHz, Rxo = 1 ohm-m) Shallow Focused Log (SFL)

7.65

195

R, from 1507 XB (for Rxo < R(), Dual-Phase Induction Log (DPIL) (40 kHz. Rxo = 1 ohm-m) 7.66

196

R, from Dual-Induction Focused Log (for R, < Rxo)

Shallow Focused Log (SFL)

7-67

197

R, from Dual-Induction Focused Log (for R( > Rxo)

7-68

198

R, from Deep Induction, Focused Log, and Rxo

7-69

199

R, from Deep Induction, Short Normal, and Rxo

7-70

200

201

Determination of Water Saturation by Archie's Formula

7-71

Determination of Water Saturation Using Rxo/Rt

7-72

202

Determination of Water Saturation in Shaly Sand

7-73

203

Determination of Water Saturation in Shaly Sand (Contd)

7-74

204

Resistivity of Mixed Waters, Rz, for Rocky Mountain Method

7-75

205

Determination of Water Saturation by Rocky Mountain Method

7-76

206

Resistivity/Porosity Crossplot (for F = f^) Resistivity/Porosity Crossplot (for F = ij)'2) Resistivity/Porosity Crossplot (for F = O.620215)

7-77 7-78 7-79

207 208 209

Determination of Rwa, Sw, and $

7-80

210

Dielectric Water Attenuation vs. Water Resistivity Relationship

7-81

211

Dielectric Water Propagation vs. Water Resistivity Relationship

7-82

212

Dielectric Response in a Homogeneous Medium (200 MHz)

7-83

213

Dielectric Response in a Homogeneous Medium (47 MHz)

7-84

214

Water Saturation from Dielectric Propagation Time (Clean Formations)

7-85

215

O Pulsed Neutron

Determination of Zw

8-1

217

Zw for Boron Compounds in Water

8-2

218

Determination of XcH4

8-3

219

Neutron Capture Cross Section of Wet Gas

8-4

220

Correction of Sgas for Condensate Content

8-5

221

Determination of Ioi| for Varying Gas/Oil Ratios

8-6

222

Water Saturation Determination from Pulsed Neutron Capture (PNC)

8-7

223

PDK-I00 Sigma Borehole and Diffusion Correction

8-8

224

Borehole Salinity Corrections for Sandstone Formation (7-in. Casing, 8-in. Borehole)

8-9

225

PDK-100 Diffusion Corrections to SGMA for Sandstone Formation (9-5/8-in. Casing, 12-in. Borehole)

8-10

226

C/O Ratio Response to Varying Lithology and Saturations

8-11

227

Inelastic Ca/Si Ratio Response to Varying Lithology and Porosity

8-12

228

Capture Si/Ca Ratio Response to Varying Lithology and Porosity

8-13

229

C/O Oil Saturation Correction vs. Cement Thickness

8-14

230

C/O Ratio Correction for Oil Density (Gravity "API)

8-15

231

Capture/Inelastic Ratio and Porosity Correlation

8-16

232

Cement Compressive Strength from Segmented Bond Tool Log

9-1

233

Cement Compressive Strength from Series 1423 Bond Attenuation Log

9-2

234

Cement Compressive Strength from Series 1456 Dual Receiver Bond Log

9-3

235

Cement Compressive Strength from Series 1412, 1415, and 1417 Cement Bond Log Instruments

9-4

236

Example Form for Information Critical to CBL Interpretation

9-5

237

Example Form for Cement Data Critical to CBL Interpretation

9-6

238

Guidelines for Practical Interpretation of Variable Density Logs and Acoustic Waveform Signature

9-7

239

Guidelines for Practical Interpretation of Variable Density Logs and Acoustic Waveform Signature

9-8

240

Casing Sizes Threaded, Coupled Type Nonupset

9-9

241

y Borehole Mechanical Integrity

Contents Section

Chart

Page

Pipe Expansion Due to Internal Pressure

9-10

242

Determining Corrosion in Tubular Goods

9-11

243

9-12

244

9-13

245

Reservoir Permeability Estimate from Log Data (Timur Equation)

10-1

247

Reservoir Permeability Estimate from Log Data (Morris and Biggs Equation)

10-2

248

Permeability from Resistivity Gradient

10-3

249

Charts and Equations to Estimate Relative Permeability to Water, Oil, or Gas

10-4

250

Chart to Estimate Viscosity of Water

10-5

251

Charts to Estimate Viscosity of Different Crude Oils

10-6

252

Charts to Estimate Viscosity of Different Natural Gases

10-7

253

Charts to Estimate Water Cut in the Transition Zone of an Oil Reservoir

10-8

254

Reservoir Producibility in Shaly Sand

10-9

255

Formation Strength Parameter Equations in Well Logging Terms

10-10

256

Interrelationships of Formation Strength Parameters

10-11

257

Interrelationships of Formation Strength Parameters

10-12

258

10-13

259

Magnelog - Wall Thickness Determination - Single String/2934MA/

Spacing: 29 in.. 7-in. P-l 10 38 #/ft Casing

Magnelog - Wall Thickness Determination - Dual String/2934 MA/ Spacing: 28 in., 9.6-in. N-80 40 #/ft and 13.3-in. K-55 68 #/ft Casing

1U Permeability, Viscosity, and Rock Properties

Determination of Combined Modulus of Strength from

Bulk Density and Compressional Travel Time

11

Miscellaneous Tables

Log-Derived Clay Content Indicators

.261

Permeability and Water Cut Determination

.263

Logging Parameters for Various Elements. Minerals, and Rock Types

.266

Densities of Mctamorphic Rocks

.275

Classification of Water Saturation Equations in Shaly Clastic Reservoir Rock

-5

276

REFERENCES

278

BIBLIOGRAPHY

280

XI

Kit ATLAS

Formation Parameters

Transition Zone or Annulus

(\ Fluid Resistivity J L Zone Water Saturation

Q Zone Resistivity

1-1

____■»■

Conventional Symbols for Well Logging and Formation Evaluation1

Utter Quanlily

Symbol

atomic number

Z

atomic weight

A

cementation (porosity) exponent

m

concentration (salinity)

C

conductivity, electric

C

correction term or correction factor

(either additive or multiplicative)

B

cross section, macroscopic

I siema

density

p rho

depth

D

diameter

d

electrochemical coefficient

K

electromotive force

E

factor

F

geometrical fraction (multiplier or factor)

G

gradient

g

gradient, geothermal

gG

cap

index (use subscripts as needed)

I

macroscopic cross section

I sigma ca

porosity (Vb - Vs)/Vb

+ phi

pressure

p

radial distance (increment along radius)

Ar

radius

r

resistivity

R

saturation

S

saturation exponent

n

slope, interval transit time vs. density (absolute value)

M

slope, neutron porosity vs. density (absolute value)

N

SP reduction due to shaliness

osp alpha

SP, static (SSP)

Essp

specific gravity

y gamma

SSP (static SP)

Espp

temperature

T

thickness

h

time

t

time difference

At

velocity

v

volume

V

volume fraction or ratio (as needed, use same subscripted symbols as for "volumes"; note that bulk volume fraction is unity and pore volume fractions are t)

V

Dimensions: L = length, m = mass, q = electrical charge, t = time, T = temperature.

1-2

WE81EHN ATIA8

Conventional Subscripts for Well Logging and Formation Evaluation2

Subscript Definition

anhydrite apparent (general) bottom hole bulk clay corrected dolomite

equivalent fluid flushed zone formation (rock) gas

geometrical geothermal grain hole hydrocarbon

intrinsic

invaded zone irreducible limestone liquid

log, derived from log, given by matrix (solids except dispersed (nonstructural) clay or shale) maximum minimum mud mud cake mud filtrate oil primary pscudo-SP relative residual sand

sandstone secondary shale silt SP, derived from SSP

surrounding formation tool, sondc total (gross) irue (opposed to apparent)

1-3

Bil

Conventional Subscripts for Well Logging and Formation Evaluation

WESTERN ATLAS

Subscript Definition

water

well flowing conditions well static conditions zero hydrocarbon saturation

%

%.

1-3 (Contd)

■Sit

WESTERN ATLAS

Unit Conversions

Kit

Unit Conversions

CRN ATLAS

Description of Core Analysis

1-5

Bil

Service Mnemonics — Products Category Listing

WESTERN ATLAS

WESTERN ATLAS

Kim

WESTERN

Service Mnemonics — Products Alphabetical Listing

10

ATLAS

Bit Common Log Presentation Formats

Linear Grid SP

DEPTH

RESISTIVITY Ohms m2/m

CONDUCTIVITY

16'Normal

Induction Conductivity

SP

Millimhos/m

Millivolts

40' Spacing

20 Rm = 0.7 0 78' Rm = 0.64 O 78'

BHT=190"8 10 500 Mean Surfacr Temp = 80*F

2

Induction Resistivity 40* Spacing

4000

0

B000

4000

1g

2lIIIIIIIl02

The time markers occur every

Induction

60 sec and can be used to

i

determine logging speed. "===-

i

*w —Amp 16" Normal a -Conductivity

SP 16'Normal -hi I I I

Split 3-Cycle Grid GR

SP

RESISTIVITY Ohms nfiltn

DEPTH

CONDUCTIVITY Mil!imhos/m

Induction Conductivity 40' ISpactng

16' Normal 0.2

40' Spacing

130

02

1.0

INDUCT1C SP

6' NORMAL

GAM

1-8 II

C

10 20

Ineuction Rosistivry

GAMMA RAY

2P

1.0

4000

eooo

B43

4000

10 20

4

CONDUCnVTTY

Bit

Well Log Scales

WESTERN ATLAS

^

%

12

ISM

WESTERN

ATLAS

BHC Acoustilog Presentation

_CALJinJ____J6| GR(API)

TRANSIT TIME (MS) 10 0 |

120.

_POROSJTY

+30

VOL (cu It) M 0 30

■10

AC IMICS/lt)

40

140

OPECHE

1011

MINNELUSA

TEN MILLISECONDS TRANSIT TIME

-

__>

POROSITY

CALIPER

INTEGRATED TIME

MARKERS

VI

BOREHOLE VOLUME

\

TENSION CURVE — TP

- Integrated Transit Time (ms)

/

1-10 13

WESTERN ATLAS

Symbols Used on Well Logs

Casing Shoe

FT-*

Cored Interval

Perforations

DST Interval

Bridge Plug

Plug

Sidewall Core

NR-*

LB-*

Formation Interval Test (Wireline)

(Cement, Sand, or Gravel)

Production Packer

Sidewall Core Attempt ■

(Single)

No Recovery

Production Packer

Sidewall Core Attempt -

(Dual — Multiple

Lost Bullet

Uses Same Format)

1

Ml 14

Map Symbols for Identifying Well Conditions

♦

Oil Producer

♦

O (D O Q

Oil and Gas Producer

Abandoned Oil and Gas Producer

Shut-in or Suspended Oil Producer

Abandoned Drilling Well with Oil Show

Gas Producer

Abandoned Gas Producer

Shut-in or Suspended

Abandoned Drilling Well with Gas Show

Gas Producer

Drilling Well or

Salt Water Disposal

Proposed Well Location SWD

Bottomhole Location "X"

Indicates Bottomhole Location

(

0

Abandoned Oil Producer

Dry Hole

(Indicate Well Status) •x

Multiple Completion Oil

Multiple Completion Gas

1-12 15

WESTERN AT1AS

WESTERN ATLAS

Paleofacies Characteristics

MATRIX

MUDSTONE

CEMENT

PORE

GRAIN

WACKESTONE

Volumetric components of sandstone

ARRANGEMENTS OF SQUARE LAYERS

CASE1

CASE 2

CASES GRAINSTONE

ARRANGEMENTS OF SIMPLE RHOMBIC LAYERS

CASE 4

CASES

CASE 6 (Dh

Six regular packing configurations of uniform spheres: Case 1,

cubic; Case 2, orthorhombic; Case 3, rhombohedral; Case 4, orthorhombic; Case 5, tetragonal; Case 6, rhombohedral.3

Samples of carbonate grain types (A) mudstone - muddy carbonate rocks containing less than 10% grains, (B) wackestone - mud supported rocks containing more than 10% grains, (C) packstone - grain-supported muddy carbonates, (D) grainstone - grain-supported, mud-free carbonate rocks.

Modes of detrital clay dispersion in sandstones

1-13 16

WESTERN ATLAS

Grain Size Scales for Sediments4

US. STANDARD

MILLIMETERS

SIEVE MESH #

(mm)

T

MICRONS phi

4096

-12

1024

-10

-

USE

—

- 256

- 8

-

WIRE

—

-

64

- 6

16

-

—

- 2

6

3.36

-

7

2.83

-

1.5

8

238

-

125

10

2.00 —

-

10

12

1.68

- 075

14

1.41

- 0.5

16

1.19

- 0.25

18

1.00 0.84

0.25

25

071

05

-

1/2

-

■500

■

420

45

1.25

0.35

350

50

1.5

0.30

300

1.75

0.25

-

-250

-

0.210

210

80

0.177

177

100

25

0.149

149

275

1/8

0.125

-

-125

225

-

0.105

105

170

0.088

86

3.25 35

0.074

74

3.75

230

1/16

0.0625 -

- 62.5 -

0.053

53

325

425

0.044

44

45

0.037

37

475

BY

PIPETTE ~ OR

HYDROMETER

I

COARSE SILT

1/32

0.031

1/64

0.0156

156

6.0

1/128

0.0078

7.8

70

3.9 -

FINE SILT

8.0

VERY FINE SILT ■

■ 1/256

-

VERY FINE SAND

- 4.0

270

-

FINE SAND

30

140

200

MEDIUM SAND

20

70

120

iff COARSE SAND

10

0.42

1/4

VERY COARSE SAND

075

0.50

40

60

GRANULE

0.0

0.59

35

PEBBLE (-2 to -6*)

1.75

20

30

1

4

4

_ ANALYZED _

BOULDER (-8 lo -12*) COBBLE (-6 lo -8*)

SQUARES 5

WENTWORTH SIZE CLASS

0.0039 -

■

-

31

-

50

0.0020

2.0

0.00098

0.98

100

0.00049

049

110

0.00024

0.24

120

0.00012

012

130

0.00006

0.06

14.0

MEDIUM SILT

9.0

CLAY

UNITS = NEGATIVE LOGARITHM TO THE BASE 2 OF THE DIAMETER IN MILLIMETERS.

1-14 17

tzil

Comparison Chart for Sorting and Sorting Classes5

SORTING IMAGES

RO

888 0.35

0.50

o( )V JO

tm 1.00

2.00

DIAMETER RATIO

PHI STANDARD

VERBAL

(mm)

DEVIATION

SCALE

1.0

00 VERY WELL SORTED

-1.6-

-0.35-

MATURE WELL SORTED

-2.0-

-0.50-

-4.0-

- 1.00-

-16.0 •

-2.00-

MODERATELY SORTED POORLY SORTED

VERY POORLY SORTED

1-15 18

SUBMATURE

WESTERN AJIAS

WESTERN ATLAS

Curve Shape Characteristics6 #

Smooth

Serrated

Cylinder-shaped curves represent uniform deposition. Characteristic environments are: Cylinder Shape

Smooth

Eolian Dunes

Tidal Sands Fluvial Channels

Bell-shaped curves represent a fining upward sequence such as:

Serrated

Tidal Sands

Bell Shape

Smooth

Deltaic Distributaries Turbidite Channels Proximal Deep Sea Fans

Serrated

Alluvial Fans Braided Streams Fluvial Channels Point Bar

Deltaic Distributaries Turbidite Channels Lacustrine Sands Proximal Deep Sea Fans

Funnel-shaped curves represent a coursening upward sequence such as: Funnel Shape

Alluvial Fans Barrier Bars Beaches

Distributary Mouth Bars Delta Marine Fringe Distal Deep Sea Fans

Crevasse Splays

Combination curve shapes may indicate gradual changes or abrupt changes from one environment to another.

Convex or concave curve shapes may indicate relative changes in water depth during deposition.

1-16 19

WESTERN ATLAS

Time-Rock Correlation

Several methods of time-rock correlation have been and are being used to describe geological age, stratigraphic sequences, etc. Some involve the traditional "layercake" methods that have served ade quately in petroleum exploration for many years. However, the days of finding giant structural traps

are mostly behind us and stratigraphic traps have taken on more significance. Lateral changes in facies, pinchouts, etc. are more important considerations today. Positions in the vertical sequence are still important but lateral facies changes and the effects of generalized, ambiguous terminology can create correlation problems.

Correlation of biostratigraphic units provides one method of correlating the time sequences, which emphasizes the importance of comparing (when possible) paleofacies evidence to the electrofacies characteristics of log measurements. Bathymetric cycles can be correlated. Time parallel strata can be correlated. Positions in a climatic cycle can be correlated. Tectonics also play an important role in the sedimentation framework.

The generalized geological timetable outlines some of the faunal, floral, climatic, and tectonic events that are reasonably well accepted by the scientific community. The intent is not to provide a geology course, but to show how geology can be correlated to log analysis in different situations.

For example, meandering streams are notably absent prior to the Devonian. They developed pri marily in the valleys and coastal areas from the Devonian until the Cretaceous because that is where the moss, ferns, and pines established themselves. By the Cretaceous, flowering plants had evolved and established themselves in the highlands, deterring the erosion process and creating more mean

dering systems. By the time grasses had evolved in Miocene time, the character of fluvial morpholo gy had reached the state of morphological development witnessed today. Therefore, there is a low

probability of a meandering stream environment in rocks older than Cretaceous and a probability of zero should be expected in rocks older than Devonian.

1-17 20

Generalized Table of Geologic Time and Occurrences of Major Tectonic, Climatic, and Palcontological Events

r

r 1-18 21

ECU

WESTERN ATLAS

Bil

Circumferential Borehole Imaging Log (CBIL) Operating Range and Mud Excluder Selection

WESTERN ATLAS

The ultrasonic attenuation of the borehole drilling fluid plays a major role in determining CBIL log quality. High values of ultrasound attenuation in either large or small diameter holes can adversely affect the desired formation image. High ultrasound attenuation in a small hole will create an interfer ence pattern (e.g., wood grain) on the image, and is caused by diminished return echo summing with

the transducer ringing and sound reverberations within the tool. Tool centralization is therefore very critical in small diameter holes. High ultrasound attenuation in large diameter holes will cause undesired speckles, fuzziness and/or streaks in the image, caused by reduced signal-to-noise ratio and beam spreading. Dark streaks or bands on the image are due to the longer sound proof caused by borehole ellipticity and/ore a decentralized tool. A new cone-shaped teflon window was designed to reduce the occurrence and severity of the interfer ence pattern when logging in small diameter boreholes |6 to 8 in. (152 mm to 203 mm)]. The slanted

surface of the window reduces acoustic reverberations between the transducer and window that inter fere with the return echo.

A new CBIL mud excluder was designed to reduce the amount of signal attuenuation in boreholes >8 in. (203 mm) in diameter. The excluder replaces the high-attenuation fluid path with a lower atten uation teflon path. The angled surface of the excluder reduces the sound reflection at the

excluder/fluid interface enabling successful CBIL images to be obtained in boreholes (in "good condi tion") that range in diameter from 6 in. (152 mm) to 12.5 in. (318 mm). Practical field experience shows that a 0.75-in. (20-mm) spacing between the excluder and the borehole wall will yield good images while limiting the risk of becoming stuck in the hole. The excluder should be used in any weighted water-base or oil-base drilling fluid. Past performance has also demonstrated that a properly installed and maintained excluder will not diminish CBIL log quality in fresh water-based fluids. The graph on this page is used to select the proper mud excluder for particular borehole sizes. Six dif

ferent excluders are available for the borehole sizes listed. Assuming "good borehole conditions" and good tool centering, the graph ensures effective operation range when the proper excludes are utilized

since they were developed for worse-case fluid attenuation. The graph area between 10.75 and 11.25 in. (273 mm to 286 mm) requires a customized excluder kit for optimum operation.

4? ^

' I ' ' 9

10

Borehole Diameter (in.)

1-19 22

12

\

12*1

WESTERN

ATLAS

Estimation of Formation Temperature Mean Surface

Formation Temperature, T, (°C)

Temperature. Tms ■4

25 t—i—[-1

16

i

i

25

i

75

50 | i

i

50

i

i

I

100 i

i

i

125

f I

i

I

100

75

150

I—I—I

1

I

125

I

150

I

I

225

200

175 [

I

I

I

I

I

I

I

I

200

175

I

I

I

I

225

' ■■ M r | i1 i' i' i1 i1 50

75

150

125

100

250

225

200

175

O

a

a

x

B, o a.

a

0.6

100

i 40

1

i

150

i

I

i

i

i

100

0,8 \

1.0

200

i

I

i

i

150

i i

\

250

I

i

i

i

1.2

"V't.4

300

i I

200

250

i

i

i

1.6

350

i I

i i

300

*

400

i i—I

I

I I

350

450

I—I—I—J—L_L 400

450

Formation Temperature, T, (°F)

Wean Surface Temperature, Trrts

Example

bg x D/ioo

Given; Total Well Depth gG -

Bottom Hole Temperature

-SS x 100

1.823 °C

100 ft

100 m

From Chart: Geothermal Gradient

= 1.2°F/100 ft

Formation Temperature at 7,000 ft

=

164°F

Note; To convert the formation temperature scale, T,CF), to a mean surface temperature, Tltls, not shown,

add or subtract the appropriate value to the entire

0.549 °F 100 m

* 200°F

Mean Surface Temperature ■ SOT

Temperature Gradient Conversions 1°F

= 10,000 ft

scale. For example, if Tllti = 40°F, the 60° tick

100 ft

mark corresponds to 4O°F, the 150" tick corresponds

to L30°F, the 300°F tick corresponds to 28OT. Kc.

2-1 23

WESTERN

ATLAS

Estimation of Rm|-and R

mt

Rml or Rmt (Q-m) 5 --

4

--

3

--

2

(Q-m) T" 6 5 - - 4

-- 3

Mud Weighl

llb/gal)

-- 2

05

(kg/m3)

16-18 _ 1920-2160

0.5 --

0.2

10 ->- 1200 0.1

■0.1

■0 05 0.05

■0.01 --

2.65

0.02

0.01

= 0-69 Example

Given: Rm = 0.7 fi ■ m at 200"F mud Mud wdglu= 12.0lli/gal

Note; This chart may be usai when ihc miasurcd values of Rn]1- and RIIX. are not

Dcierminc: Rmf and Rmc Rmf = 0.4i2.mal200°F RmL- = 1.2 LI ■ m at 200"F (from eqiiaiion)

24

available, but does not apply to lignosulfonate muds.

WESTERN

nuns

Determination of Static Bottomholc Formation Temperature

245

240 115

Slalic Temperature

235

230

110

225

o

f 105 o o

eS

iu:

D.1

0.2

0,3

0.4

0.5

0.6

0.7

I

I

0.8

0.9

210

1.0

At/(l + At)

This chan is used io predict the static boltomhoie formation icrnperature by recording the bottomhole temperature on each successive trip in the well. Each bottcunhole temperature is plotted vs. the borehole fluid circulation time relationship on a siimilog graph. Passing a straight line through llie plotted points to the right ordinate will provide an estimation of the static bottomhole formation temperature. Example

Run

At t + Ae

Run 2

At

Dimension I ess

Buiiomhole

Time

Temporal Luv

0.538

220°FU04"C)

0.671

225°F (IQ7CC)

0.7fi5

228°F

t + At

Run 3

At

t + At

4.5

i = circulation time (hr)

At = time after circulation stopped (hr)

Static Temperature - 234°F (!12CC) 2-3 25

E

Equivalent NaCl Concentrations from Total Solids Concentrations

26

WESTERN ATLAS

Resistivity of Equivalent NaCl Solutions

27

WESTERN

Total Salinity Versus Density of Different Solutions

Supersaturated Konnuliun Waters

Salt-saturated brine is commonly accepted to he about 260.000 ppm; however, thai is irue for NaCI solutions. Formation water can on occasion be supersaturated with CnCh salts and provide

an explanation for unusual log responses and/or log analysis results with respect to conventional log interpretation charts or algorithms. A chan comparing total salinity versus density of solutions is provided to exhibit CaCli solutions reaching the saturation point at abow 500,000 ppm. and represeniinj; ;i solution density of 1.5 g/cnr*. When such solutions are found as formation water, thu neu tron log is severely affected by the abnormal salinity, ami fluid density used for calculating density porosity is often pessimistically low in value. When ■ hypersaline condition exists, it often requires some local wizardry to design empirical log analysis charts to lit the unusual conditions.

0-9 100

200

300

400

Total Salinity, (kppm)

2-6

500

000

ATLAS

WESTERN ATLAS

Variation of Brine Density with Temperature and Pressure7 460 -225

400

-200

350 -

300 O

250

200 -

150 -

-50

100

-25

0.86

0.90

0.94

0.98

1.02 ^

106

1-10

1.14

1.18

Density (g/cm^ or Mg/m3)

The relationship expressed by this chart,

p = 0.9974 + 8.O3X1O-4S+ I.78X1O"6P- I0"4 <1.07 + 1.578X10 2S - 2.54XI0-4P) T - lO"6 (2.75 - 7.3X10'3S + 3X1O"5P) T2. where S is salinity in kppM by weight NaCI, P is pressure in lb/in.2, T is temperature in

°C, and r is density in g/cm3, reproduces the reference1 data in the range 10<S<250,

0
2) Interpolate to find the density of 180 kppm salt water at 4,350 psi and 302°F. 3) Interpolate between I) and 2) to find the required density = 1.036 g/cm3.

2-7 29

WESTERN

Comparison of Temperature Gradient Steepness and Lithology

AT1AS

Temperature Increases Limestone

. Shale

Dolomite

Gypsum

Anhydrite

Sandstone

2-8 30

\

WESTERN

Brine Density as a Function of Fluid Salinity and Formation

ATLAS

Temperature and Pressure Salinity (kppM)

I

i

450

|

i

i

I

100

50

i

I

|

150

200

250

400

350

~

i

300

|

I

250

200

150

100

9,000 8,000 7.000 6,000

5,000

4,000

3,000

2,000

1.000 ATM 0.90

Brine

Density (g/cm3) I

■

'

'

'

0.95

I

'

'

'

'

1.00

I

i

i

I—I

T I

I

I

I

i

'

i

■

I

The relationship expressed by this chart,

pBr (g/cm3) = 1.066 + 7.4X IO-4S(kppM) - 2.5X IO-7[T(°F)+47312 + P(psi)/1.9X105, reproduces data from USGS Bulletin I421-C with an rms error of 0.004 g/cm3, for typical downhole temperatures and pressures (25 < P(psi)/[T(°F)-80] < 55). It is less accurate outside these limits.

2-9 31

1.20

WESTERN

ATLAS

SP lied Thickness Correction

3.5

2.5 CD

1.5

1.0

1.2

1.5

2-0

2.5

30

4.0

5.0

6.0

7.0

8,0

SP Correction Factor 1

SP correction factor =

h - ■ ■ Ri for

-1.5

R

— >5

+ 0.95

II

/0.65>

6.05

- 0.1

und 3
SSP - SP X SP correction factor

Given: SP^ = - 50 mV; h = 8 ft; R^ = 35 Q"m; R,n = O.7£2-m

Solution: Bed thickness = 8 ft; R/Rm = 50; SP correction factor = 1.42 Noniogmph Solution: SPlog = - 50 mV; SP correction factor = 1.42; SSP = - 71 mV

3-1

9.0 10.0

KSil

Rw

WESTERN ATLAS

from the SSP

-200

500°F 250°C -175

400° F 200°C -150

3O0°F

150°C

-125

% -100 a" -75

3

-50

I

50

75

0.3

0.5

1.0

3.0

5.0

10.0

30.0

Using Tf in °F; SSP = - (60 + 0.133 Tf)log

Example *eq

HSSP

T

(60 + 0.133 Tr) I'

Given: SSP = - 71 mV; Tf = 140°F; R^ = 0.55Q-m

Determine: Rwea since Rmf/Rwea = 8.0 =0.55/8.0 = 0.069 Q-m

°F = 1.8 (°Q + 32

3-2 34

Rw from Uw i

E

05

H

0.2

ri

01

-

005

r

0.02

r

0.01

-

as a Function of Temperature (°F)

3. ' -_ EC

5

0005 -

0.002 r

0001

0.005

0.01

0.02 0.03

0.05

0.1

0.2

0.3

0.5

1

R,, orRm(.(Q-m)

English: fL

+ 0.131 x

- 0 5 R

iol"l°snVl9.'»]-2

11

Example

Given: 1^,

= 0.069 Q-m, Tr = 140°F

Dclenninc: Rw; R^. = 0.073 B'm al 140°F.

For mosily NaCl formation waters, use the solid lines. Use the dashed lines for fresh formation waters thai are being influenced by siilt.s other than NaCl, and for gypsum-based muds. 3-3

WESTERN ATLAS

n

o

§

s

o

I

V)

i

©

KS1I

WESTERN ATLAS

Gamma Ray Borehole Size and Mud Weight Correction for a l'Vifi-in. Diameter Instrument

7 6 5 4

-

3 -

Q

2 -

o

1 0.9

OS 0.7 0.6 0.5

12

20

16

Borehole Diameler (in.)

Decentralized Centralized

For decentralized tool: Borehole diameter in inches Mud weight in Ib/gal

For air in borehole (decentralized): A -

0.675827

B =

0.0045061

C =

0.00074056

For centralized tool:

A = 0.667925 - 0.0094607 x W - 0.00009904 X W2 B 0.045183 + 0.0012987 x W + 0.00010822 x W2 C = -0.014169 + 0.0019549 x W - 0.00001368 x W2 Chart provides correctioas to 7%-in., freshwater-filled borehole, with instrument decentralized.

4-1 37

Gamma Ray Borehole Si/e and Mud Weight Correction

WESTERN ATLAS

for a ln/u.-in. (43-nini) Diameter Instrument

^

IE

a

ID

100

200

300

400

Borehole Diameter (mm)

500

Deconlralized Cenlrali?ed

For decentralized tool:

A a

0.822149 - 0.2948092 x W + 0.05460770 x W3

B = -0.033622 + 0.0716393 X W - 0.01295763 X W2

C =

0.000530 - 0.0009257 X W + 0.00018812 x W2

and

D

W

Borehole diameler in centimeters

Mud weight in g/cm-1

For air in borehole (decentralized): A =

0.675827

B =

0.0017741

C =

0.00011479

For centralized tool: A =

0.667925 - 0.0789020 x W

0.00688849 x W2

B =

0.017788 + 0.0042644 x W

0.00296362 X W2 0.00014745 X W2

C =

-0.002196 + 0.0025271

x W

Chart provides corrections to 77s-in. (200-mm), fresh-watur-filled borehole, with instrumem decentralized.

4-2 38

KSifl

WESTERN

Gamma Riiy Borehole Size and Mud Weight Correction

ATLAS

for a 35/s-in. Diameter Instrument

3

—

2

-

CE

1

09 0.8 07 0.6

05

8

10

12

14

16

IB

20

Borehole Diameter (in,)

Decentralized

Centralized

GRco/GRiog = A+BxD+CxD2 For dccentruSizcd tiKil:

A -

1.278627 - 0.12390I6 X W + 0.00352223

x W^

B -

-0.135629 + O.O33I273 x W - 0.00088511

X W^

C -

0.003407 - 0.0008101

and

I> = Borehole diameter in indies W = Mud weight in \blgti

X W + 0,00002193 x W?

For air in borehole (decentralized); A

-

0.696160

B

=

0.0148190

C

-

O.OOO23S21

For centralized ton);

A =

B

=

C

=

0.390412 + 0.0350544 x W - 0.00146984 X W?

0.153958 - 0.0181037 x W -t- 0.00050879 x W? -0.017859 + 0.0028769 x W - 0.00004882

x W^

Chart provides correciioas la 7%-in., freshwater-filled borehole, with instrument decentralized.

4-3 39

Gamma Ray Borehole Size and Mud Weight Correction for a 35/st.-in. (92-mm) Diameter Instrument

40

WESTERN ATLAS

Spectralog Total Gamma Ray Response

Borehole Size and Mud Weight Correction

41

WESTERN

ATLAS

IBM

Spectralog Total Gamma Ray Response Borehole Size and Mud Weight Correction

WESTERN ATLAS

2.5

1.5

05

10

20

30

40

Borehole Diameter (cm)

Correction Chart Equation (decentralized):

where

A =

0.621115

+

0.0054355 X W

-

0.00087780 X W2

B =

0.080813

-

0.0034177 x W

+

0.00032912 x W2

C = -0.002796

+

0.0002633 X W

-

0.00001398 X W2

and

D = Borehole diameter in inches

W = Mud weight in lb/gal

Chart provides corrections to 6-in., freshwater-filled borehole, with instrument decentralized.

Note: The tool is generally run decentralized.

4-6 42

50

Spectralog Uranium Response

ATLAS

Borehole Size and Mud Weight Correction

2.5

1.5 -

0.5

8

10

12

14

16

Borehole Diameter (in.)

Correction Chart Equation

where

A =

0.541400 B = 0.101233 C = - 0.002612

+

0.0059536 X W

+

0.0045605 x W 0.0001865 x W

+ -

0.00073206 x W2

0.00035343 x W> 0.00001150 X W2

and D = Borehole diameter in inches W = Mud weight in lb/gal Chart provides corrections to 6-in., freshwater-filled borehole, with instrument decentralized.

Note: The tool is generally run decentralized.

4-7 43

18

20

Spectralog Uranium Response

WESTERN

ATLAS

Borehole Size and Mud Weight Correction %v

10

20

30

40

50

Borehole Diameter (cm)

Correction Chart Equation (decentralized):

where

A = 0.541400 B = 0.039856 C = - 0.000405

+ +

0.0496528 X W 0.0149743 X W 0.0002410 X W

+ -

0.05091912 X W2 0.00967845 X W2 0.00012394 X W2

and

D = Borehole diameter in centimeters W = Mud weight in g/cm3

Chart provides corrections to 6-in. (15.24-cm), freshwater-filled borehole, with instrument decentralized.

Note: The tool is generally run decentralized.

%k

4-8 44

WESTERN

Spectralog Potassium Response

ATLAS

Borehole Size and Mud Weight Correction

2.5

1.5

0.5

8

10

12

14

16

Borehole Diameter (in.)

Correction Chart Equation (decentralized): \r

tic*

r^Qf/IVjQp

^ —

a

r\

ji

u

D

v

A

r^

LI

_L.

~r

r* w

n/

^

r\5

L/^

where

A = B =

0.611194 0.067880

C = - 0.001902

+ 0.0038498 x W - 0.00098837 x W2 - 0.0006362 X W + 0.00028139 X W2

+ 0.0000805 X W -

0.00000924 X W2

and

D = Borehole diameter in inches W = Mud weight in lb/gal

Chart provides corrections to 6-in., freshwater-filled borehole, with instrument decentralized.

Note: The tool is generally run decentralized.

4-9 45

18

20

Spectralog Potassium Response

ATLAS

Borehole Size and Mud Weight Correction

15

05 10

20

30

40

50

^v

Borehole Diameter (cm)

Correction Chart Equation (decentralized):

where

A =

0.611194

+

0.0321077 x W

-

0.06874695 X W2

B = 0.026725 C = - 0.000295

+

0.0020889 X W 0.0001040 X W

+ -

0.00770559 x W2 0.00009958 x W2

and D = Borehole diameter in centimeters

W = Mud weight in g/cm3 Chart provides corrections to 6-in. (15.24-cm), freshwater-filled borehole, with instrument decentralized.

^

Note: The tool is generally run decentralized.

4-10 46

Spectralog Thorium Response

inui

ATLAS

Borehole Size and Mud Weight Correction

25

English

1.5

05

j

i

l

i

8

10

I

12

14

16

18

Borehole Diameter (in.)

Correction Chart Equation (decentralized):

where

A = 1.156151 B = - 0.022915 C = 0.000094

+ -

0.6601228 X W 0.0621355 X W 0.0003399 X W

+ +

0.15548819 x W2 0.01401322 x W2 0.00009242 x W2

and

D = Borehole diameter in centimeters W = Mud weight in g/cm3

Chart provides corrections to 6-in. (15.24-cm), freshwater-filled borehole, with instrument decentralized.

Note: The tool is generally run decentralized.

441 47

20

WESTERN

Spectralog Thorium Response Borehole Size and Mud Weight Correction

ATLAS

\

s

20

30

40

Borehole Diameter (cm)

Correction Chart Equation (decentralized):

where A =

1.156151 B =-0.058205

+

0.0791514 X W 0.0189238 x W

+

-

0.00223545 X W2 0.00051173 x W2

C =

-

0.0002629 x W

+

0.00000857 x W2

0.000606

and D = Borehole diameter in inches W = Mud weight in lb/gal

Chart provides corrections to 6-in., freshwater-filled borehole, with instrument decentralized.

Note: The tool is generally run decentralized.

4-12 48

SO

\

Gramma Ray Correction for KCI Mud

35/«-in. Diameter Instrument (Decentralized)

■',<'

KM

WESTERN ATLAS

WESTERN

GaHUBQ Ray Correction for KCl Mud

ATLAS

3?/s-in. (92-mm) Diameter Instrument (Decentralized)

100

90

-

80 -

30

20 -

10

-

10

20

40

30

50

Borehole Diameter (cm) KCl Correction Chart liquation (decentralized) With KCl mud. first determine the borehole corrections for hole size and mud weight from Chart 4-4. Then apply this

KCl correction for the influence of KCl in the borehole.

where FGR

=

borehole size and mud weight correction
KCl

=

KCl correction in API units

=

f x KCl,.4

KCI, 4 a

from Chart 3-4)

KCl correction in API units for 1.4 g/cm' mud (from chart)

or

=

a + bxD + cxEP

-

-0.5536

where

a

b c

- 2.1434

x P +

0.01484

x P2

0.06738 + 0.2544 x P - O.OOI763 x P3 -0.0007875 - 0.002349 x P + 0.00001640 x P2

D

=

Borehole diameter in centimeters

I1

=

Percent KCl in mud by weight

f

=

borehole KCl mud weight correaion factor (normalized to

and

1.4 g/cm-1) or

W

=

3.780 - 2.538

_

weight of mud containing KCl in g/cm-'

x W + 0.4211

x W^

Note: The tool is generally run decentralized.

4-14

ifiil

WESTERN

ATLAS

Spectralog Total Gamma Ray Correction for KCl Mud 100

90

=

-

70

a.

<

60

-

50 o

O 40

30

20

10

a

io

12

14

16

10

20

Borehole Diameter (in.)

KCl Correction Chart Equation (decentralized) Wiili KCl mud, first determine ihe borehole corrections for hole size and mud weighl from Chart 4-5. Then apply this KCl correction for the influence of KCl in ihe borehole.

GR™

- FCR |GRlog - KCl]

FCiB

= borehole size and mud weighi correclion (GR^GR^

Example

where

KCl

=

from Chart 3-5)

KCl correction in API units

= f x KCl!, KC1|2

= KCl correction in API units for 12 Ib/gal mud (from chart) or

Given:

GRi^

=

211.4 API

D

=

8 in.

W

=16 Ib/gal

P

=

12% KCl by weight

FGK

=

1.23

Determine:

where a

=

b

= -0.02194

0.06541

1.1079

x P - 0.04823

x pi

KC1,:

-

+ 0.3199

x P + 0.01534

x P-

KCl

=

10.7 API

f

=

0.540

-

246.9 API

-

C

=

D

= Borehole diameter in inches

0.001074 - 0.00394 x P - 0.0005598 X P^

P

= Percent KCl in mud by weJgJtt

19.9 API

No KCl correction is needed for

and

f

= borehole KCl mud weighi correclion factor (normalized to

12 Ib/gal from chart)

the Spectra)og uranium or thorium scries response.

or

= 4.420 - 0.4126 x W + 0.01063 x \V^ W

= weight of mud containing KCl in Ib/gal

Nole: The tool is generally run decentralized.

4-15 51

ISSifl

WESTERN

ATLAS

Spectralog Total Gamma Ray Correction lor KCl Mud 100

90

80

£ a.

<

70 -

60

50 o

o ■10

30 -

20

10

2D

10

30

50

40

Borehole Diameter (cm)

KCl Correction Chart Equation (dccenrdlized)

With KCl mud, first determine ilie borehole corrections for hole size and mud weight from Chan 4-6. Then apply this KC) correction for the influence of KCl in the borehole.

GRcor

" PGR

FGR

= borehole size and mud weight correction (GR^/GR,

KCl

=

Example

where

KCI| 4

from Chart 3-6)

Given: =

58.4 API

= f X KCl|.4

D

as

20.32 centimciers

= KCl correction in AP! units for 1.4 g/cm3 mud (from chart)

W

= 2.158 g/cm3

KCl correction in API uniis

Or

P

=

12% KCl by weight

o

1.28

Determine:

where

a

=

b

= -0.008637

0.06541

- 1.1079

x P - 0.04823

x P^

+ 0.1259

x P + 0.006038

x P

c

-

D

= Borehole diameter in centimeters

P

= Percent KCl in mud by weigh!

f

as borehole KCl mud weight correction factor (normalized to

0.0001665 - 0.0006103 x P - 0.00008677 X V-

1.4 g/cm3)

19.9 API

8.7 API

f

0.439

No KCl correction is needed for the Spectralog uranium or thorium series response.

or

= 4.420 - 3.441

=

KCl

63.6 API

and

W

KC1I4

x W + 0.7397 x W^

= weight of mud containing KCl in g/cnv1

Note: The lool is generally run decentralized.

4-16 52

WESTERN

ATLAS

Spectralog Potassium Correction lor KCI Mud

7 -

6 -

5

I

-

4

o

O

3

-

2

-

1

-

io

14

16

18

20

Borehole Diameter (in.)

KCI Correction Chan Equation (decentralized) With KCI mud. first determine the borehole corrections for hole size and mud weight from Chart 4-9. Then apply this KCI correction for the influence of KCI in the borehole.

where = borehole size and mud weight correction

KCI

=

KCI correction in percent

= f x KC!12 KCI 12

=

KCI correction in percent for 12 Ib/gal mud (from chart)

or

where a

=

b

- -0.004739

0.01521

- 0.08913

x P - 0.002202

x

+ 0.02689

xP + 0.0006576

c

=

x

D

= Borehole diameter in inches

P

= Percent KCI in mud by weight

t

= borehole KCI mud weight correction factor (nomaBzed to

0.0001496 - 0.0006354 x 1> - 0.00001382 X

and

12 Ib/gal)

No KCI correction is needed for the Spec I nil og uranium or thorium series response.

or

= 1.722 - 0.03389 x W - 0.002190 x W W

Note: The tool is generally run decentralized.

= weight of mud containing KCI in lb/gal

4-17

BU

WESTERN ATLAS

Spectralog Potassium Correction for KCI Mud

c

is

a.

a

u

10

20

30

40

50

Borehole Diameter (cm)

KCI Correction Chart Equation (decentralized) With KCI mud. first determine the borehole corrections for hole size and mud weight from Cluin 4-10. Then apply this KCI correction for the influence of KCI in the borehole.

- fgr where

SJHO and mud weight correction (K41ir/K| KCI

from Chan 3-10)

= KCI correction in percent = f x KCI, j

KCI 1,4

- KCI correction in percent for 1.4 g/cm3 mud (from chart) or

where a

=

b

= -0.001866

0.01521

- 0.08913

x P - 0.002202

x P^

+ 0.01059

x P + 0.0002589

c

=

x P=

I)

= Borehole diameier in CODtlmMera

I'

= Percent KCI in mud by weight

0.00002319 - 0.00009848 x P - 0.000002142 x P^

No KCI corre«iiin is needed for

and

the Spectralog ur;Lnium or

= borehole KCI mud weight correction factor (nomadized to

thorium series response.

1.4 g/cm3) or

= 1.722 - 0.2826 x W - 0.1523 x W: W

= weight of mud containing KCI in g/em:1

Nole: The tool is generally run decentralized.

4-1S

ISM

WESTERN ATLAS

Shale Volume from Radioactivity Index

0)

E

o 4)

I

Stiebei

Larionov (Older rocks)—*r*

Larionov Tertian rocks!

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Radioactivity Index, IRA

Ira-

RA - RAc]ean sand

Clavier, et al:

RAsh ~ RAcleansand

Vsh = 1.7 - [3.38 - (IRA

where:

Stieber:

RA = Radioactivity log reading in zone of interest

.0 - 2.0 IRA)

(South Louisiana Miocene and Pliocene)

RAcJean = Radioactivity log reading in a clean

shale-free zone RAsh = Radioactivity log reading in a shale Larionov:

(Older rocks), Vsh = 0.33 (22 x 'ra - 1.0) (Tertiary rocks), Vsh = 0.083 (23-7 * 'ra - 1.0) Example

Given: Clean sand = 15 API units, shale = 90 API units, zone of interest = 40 API units, formation = Tertiary rocks Determine:

40 " 15

90—15

0.33, % V,h =

4-19 55

ATIA8

\

56

Spectralog Mineral Estimates

100 Kaolinite

Chlorite 10.0

Th/K

Clay 2

Glauconite

1.0

Feldspars

Clay 1

10

15 Th(ppm)

20

0.1

25

►

01

2345

6789

10

Estimating apparent clay. mica, feldspar, etc. from Pe vs. Th/K

Modified model of feldspar and two clay types

ratio

An empirical model to estimate proportions of feldspar and two clay types

4-21 57

WESTERN

ATLAS

Rxo from Micro Laterolog

4.0

Mudcake Thickness, hmc 3.0

of 2.0 S

20

I

I

I

30

40

50

I

I

Mudcake Thickness, hmc:

0 in- Rxo = K in.:

in.:

- 7.7255 x 10"*

—=— = 1.0342 + 0.0018

Rxo RMLL

in.:

- 1.8153 X 10"4

= 0.9176 + 0.0924

+ 2.0578 X 10-3 ^V - 5.4619 x !<>-•

Rmc

MULL

1 in.:

Rxo

+ 1.0917 x 1O"«

= 0.9970 + 0.0168 I —=tfc

= 0.55607 + 0.4641

Equations valid while

MLL

^ R

2.2353 x 10~3

- 0.0225

xo

< 100, and,

5-1 59

j

< 10.

Rmll\3

)

I

I

WESTERN ATLAS

Borehole Size Correction for Micro Laterolog (Series 1233,1236,3104 K = 0.01439) K = tool calibration factor ("K-factor") in ohmm/ohm Thick Beds

Normalized to: 8-in. borehole RMLLapp/Rm = Homogeneous medium

1000 RMLL/R

5-2 60

10000

Minilog® and Rxo Determination

61

WESTERN ATLAS

WESTERN ATLAS

62

Borehole Size Correction for Thin-Bed Resistivity Tool (TBRT)

WESTERN ATLAS

(Series 1236 XB K = 0.00352) K = tool calibration factor ("K-factor") in ohm-m/ohm PRELIMINARY (Field Test Support)

Normalized to: 8-in. borehole

RTBRTapp/Rm = Homogeneous medium

1000

RTBRT/R

5-5 63

10000

WESTERN

ATLAS

Conductivity-Derived, Water-Filled Porosity 10,000

3-

500

0.01

0.Q2

1000

0.03 0.040,05

This chart, based on F = l/<j>\ can be used to quickly

Example

derive the water-filled porosity from Rw or R^f as in

Given; C= 20 mmho/m (50 Q-m), R^, = 0.5

dicated by conductivity or resistivity measuring devices.

Determine: <j>w; $w = 10%

4> s (a RJB^V* *= [(a R^ x C)/1000]1/in

Note: Total porosity estimates from this chart

where,

are valid only in water-filled formations, If

a =

§w < ^Toial- '^e difference is an estimate of

1.0, m - 2.0

hydrocarbon-filled pure

6-1 65

KSM

WESTERN

Density Porosity and Shaliness Correction

ATLAS

ibr Constant pf and Varying pf

(g/cm3) Ptl (kg/m3 3.1 -EE-3100

Shaiiness

Porosity (%)

(lor p( = 1.0 g/cm3

Corrected

(tor P( * 1.0 g/cm3

or 1000 kg/m3)

Porosity (%)

Porosity (%)

3.0 -= E- 3000

2.9 -= 5- 2900

Of 1000 kg/m3) 2

40

2.8 -= '— 2800 ■10 2.7 — - 2700

■15

2.6

■2600 ■20

Pmo (kg/m3) 2.9 -r 2900

2.5 — - 2500

■25

2.8 2.4

-2400

■30

2.3 — —2300

• 35 Grain Density ol Formation Matrix

■2200

2.1

g/cm3

kg/m3

Sandstone

2.65

2650

Limestone

2.71

2710

Dolomite

2.85

2850

5 2

v h

-40 10

IBM 0

/

20

/

30

y

40

50

S ^ (2.2) (2.3)

■2100

2400

2200

2300 , <*

2500

(2.6) 2.0-

2600

-2000

Density porosity is corrected for shaiiness by application of V5h as determined from Chan 4-19. The chart is

mathematically correct when /i^ = 2.71 g/cm3, or 2710 kg/m3, and provides reasonably accurate corrections with other grain densities.

.

=

Pma -

Pf

'sh

V

\Pma " Pf

Example

Given: pb = 2.20 g/cnv\ Pma = 2.65 g/cm3, />sll = 2.50 g/cm3. Vsh = 20%. p{ = 1.15 g/cm3 Detemiine: Porosity

$ = 27% (for pf - 1.0 g/cm3), i[)t,ir = 25% if

= 27.55? (for (if = 1.15 g/cm3 6-2 66

Porosity and Gas Saturation in Empty Boreholes Density and Hydrogen Index oi1 the Gas Assumed to be Zero

WESTERN ATLAS

--15

20

25 --30 40

50 60

80 100 150 200 300 400 600 1000 2000 10.000

Use Only il SA = 0

(kg/m3!

2000

Bulk Density, p

(9'cm3)

200

210

22Q

230

24Q

25Q

26Q

27Q

38o

This chart determines dry gas saturation and porosity in empty boreholes using:

Sg

= 1 - Sr = 1 - (So 4- Sw)

TR, Example Given:

/ib-2.15g/cm3;pma - 2.65 g/cm3; <((„ - 10%: R, = lOfim; Rw -0.1 Qm Determine: $

= 22.7%; S,, = 56%

6-3 67

WESTERN

Acoustic Porosity and Shaliness Correction

ATLAS

for Constant Atf and Varying Atf

Shale Correction

Corrected

Acoustic porosity is corrected for shaliness by application of Vsh as determined from Chart 4-19. The chart

provides a good approximation when Atina = 55.5 ps/ft, but also provides reasonably accurate corrections with other matrix values.

Example

Given: Consolidated formation (limestone). At(k]g) = 62/w/ft. Atma = 50 /is/ft Determine: Porosity. = 11%'

Given: Unconsolidated sand (slightly shaly). At,, , = 121 /w/ft. Atsll = 135 pS/ft Vu~= 18,000 ft/s. Vsh = 10%. Alf - 244 111-4

3"

L

Determine; Porosity, q>untllr = 36%, (Jft(,r = 30% (for Alf - 190 ps/ft)

$m = 24% (for Atf - 240 ps/ft)

For consolidated formations, d>=

At - AW

—

For unconsolidated formations, 100

-

V,.

6-4 68

■V sh

U " At,,

WESTERN ATLA5

Acoustic Porosity and Shaliness Correction for Constant Atj- and Varying Atf (Metric)

Shale Correction

Corrected

PDrosity, ^ (%) 0

600 —

'250

300

&

**

Acoustic porosity is corrected for shaliness by application of Vsh as determined from Chart 4-19- The chart provides a good approximation when At^ — 1R2 jis/m, hut also provides reasonably accurate corrections with other matrix values.

Example

Given: Consolidated formation (limestone), dk^, = fis/m, Atm;| = 150 (is Determine: Porosity, $ = U9S Given: Uncon soli dated sand (slightly shaly), At,^ = 400 ^s/m, itsh = 450 = 800

Determine: Porosity,

- 36%, $mv - 30% (for Atf = 615

(t>cor = 24% (for it,- - 800 fts For consolidated formations, At - At,,,.,

For unconsolidated formations,

At - Al, / 328

/Atsh - At,, sh 1

A'f" 6-5 69

-V sh

Acoustic Porosity Determination (Clean Formations)

70

WESTERN

ATLAS

ISM

WESTERN

Acoustic Porosity Determination

ATLAS

(Clean Formations)

Dolomite

Acoustic Porosity, 200

,100

300

400

500

600

700

100

90

At,

I70 E E

Wyllie-Rose -

4tma = 43.5 us/ft

80

= 189 |is/ft

Raymer et al. (orig.)

50

s« 20 10 0

-10

25

50

_L

I

I

I

I

75

100

125

150

175

200

225

Acoustic Travel Time OiS/ft) J,

Wyllie-Rose

4>ac = -

Atf " Atma

Raymer et al. 11/2

— where,

Atn a =

2xAtf

- 1

The above computed porosities can be corrected for shale volume by using either Chart 6-4 or 6-5.

/PS

6-6 (Contd) 71

HSil

WESTERN

Pe Borehole Size Correction in Air and Water

ATLAS

(for Compensated Z-Densilog - Series 2222) Borehole Size (mm) 150

200

250

350

300

-0.5

400

I

10

11

12

13

15

Borehole Size (in.)

pe

~ pe.

+ (Pe Correction)

Example

(Water-filled borehole)

Given: P

= ].7 barns/electron

Borehole Size =11.5 in.

Determine: P. Pe

cor

- 1.7 4- 0.15 = 1.85 barns/electron

6-7 72

WESTERN

Pe Borehole Si/e Correction in Water-Based Baritc Mud

AfLAS

(for Compensated Z-Densilog - Series 2222) Borehole Size (mmj 200

250

300

350

400

.-4.0

-4.5 10

11

12

13

16

Borehole Size (in.)

Pe

= Pei

+ (P, Correction)

Example Given: P,

log

= 1.7 bams/electron

Borehole Size = 13 in. Mud Weight i- 12 Ib.'gal Determine:

Pe

6-8 73

=1.7 + (-0.62) = 1.08 barns/electron

WESTERN

Bulk Density Borehole Size Correction

ATLAS

(for Compensated Z-Densilog-Series 2222)

Fresh water. Filled Borehole

S

10 ppg Mud m Borehole

006

_

002

% 002

006

c

6

I ...

o

U

| -004

20

2J

24

26

-006

26

22

Log Density (g/cm3 ot Mg/m')

24

26

28

Log Density (g/cm1 or Mg/m3)

14 ppg f.fud m Bc'ehole

18 ppg Mud in Borenole

B

"e a;

oo2

c

9

i -002 =

% -002 a

22

24

26

28

22

Log Oonsity (g/cmJ or Mg/m3)

24

26

28

Log Density (gjfcm3 or Mg/m3i

Note: Borehole fluid corrections to density readings depend only on the mud density and not on the type ot weighting material used.

20

21

22

23

24

2S

26

27

2.8

29

30

Log Density (gUcm' or Mg/m3)

6-9 74

WESTERN ATLAS

Bulk Density Borehole Size Correction (for Compensated Densilog-Series 2227)

10 ppg Mud in Borehole

008

_

I

006

X

I

% 002 c

a

| °00 >■

1-002

22

006

I o

1

S

24

26

2 2

24

25

Log Densily (g/cm3 or Mg/m3)

Log Densely (g/cm3 or Mg/m3)

14 ppg Mud m Borehole

18 ppg Mud m Borehole

2.8

-

004

S

0M

002

S

002

I

S g

ooo

>■

24

26

2S

20

22

ensity (g'cm1 or Mg/m3)

0.18

0.14

£

0.12

material used.

5

§ 0.10

I 0.08 5

O

0.06

S

0.04

0 0.02 0.00

•0.02

2.0

26

28

30

Note: Borehole fluid corrections to density readings depend only on the mud density and not on the type of weighting

0.16

_

24

Log Density (g/cm3 or Mg/m3)

2.1

2.2

2.3

2.4

2.6

2.6

2.7

2.8

2.9

3.0

Log Densily (g/cm3 or Mg/m3)

6-10 75

WESTERN

Compensated Neutron Borehole Size Correction

ATLAS

(for Series 2418 CN Log)

15

20

25

Apparent Limestone Porosity, +

Borehole Size

30

(%)

Equation

4-3/4 in.

<(,cor = 1.08 <(>a + 1.38

6-1/4 in.

♦cor = 1.04
7-7/8 in.

0cor = ^a

10-5/8 in.

<(.cor = 0.9268 <|>a - 0.96

14 in.

<(>cor = 0.8462 ^ - 1.46

6-11 76

35

40

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log)

0 ppm NaCI Equivalent Borehole Fluid

0) o

■o

9 o

O

5

10

15

20

25

30

35

40

45

40

45

Apparent Limestone Porosity, |a(°/o)

0 ppm NaCI Equivalent Borehole Fluid

45

40

35

#

100 mm

30

t

25

<S

20

I

15

S

10

-5

-5

150 mm 200mm 250 mm

0

5

10

15

20

25

30

Apparent Limestone Porosity, +a{%)

6-12 77

35

Compensated Neutron Borehole Size and Salinity Correction

WESTERN ATLAS

(for Series 2420 CN Log)

50,000 ppm NaCI Equivalent Borehole Fluid

5

10

15

20

25

30

35

40

45

Apparent Limestone Porosity,
1 45

40

50,000 ppm NaCI Equivalent Borehole Fluid

Metric

35

#

J 3° 8

25

»

20

1

15

§ 8

Borehole 100 mm Size 150 mm 200 mm 250 mm

10 >300 mm

5

•350 mm • 500 mm

0

-5 -5

5

10

15

20

25

30

Apparent Limestone Porosity, 4a{%)

6-13 78

35

40

45

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log)

100,000 ppm NaCI Equivalent Borehole Fluid

5

10

15

20

25

30

35

40

45

Apparent Limestone Porosity,
100,000 ppm NaCI Equivalent Borehole Fluid

45

40

I

J *

Metric

350 mm ■

35

30

£

25

100 mm

|

20

200 mm

3

15

s

10

150 mm

is

E

500 mm ■

Size

300 mm -

IB

£

Borehole

250 mm

5

0 -5

-5

0

5

10

15

20

25

30

Apparent Limestone Porosity, 4a(%)

6-14 79

35

40

45

WESTERN ATLAS

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log)

150,000 ppm NaCI Equivalent Borehole Fluid 45

40

35

% 30 t

25

0

20

1

15

|

10

8

.

I

0 -5

-5

0

5

10

15

20

25

30

35

40

45

40

45

Apparent Limestone Porosity, 4>a(%)

45

150,000 ppm NaCI Equivalent Borehole Fluid

40

35

30

25

£ 20

10

5

0 -5 -5

5

10

15

20

25

30

Apparent Limestone Porosity, <|>a(%)

6-15 80

35

WESIERH ATLAS

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log)

200,000 ppm NaCI Equivalent Borehole Fluid

45

40

35

30

25

20

15

10 O

o

5

-5

-5

0

5

10

15

20

25

30

35

40

45

Apparent Limestone Porosity, 4>a(%)

200,000 ppm NaCI Equivalent Borehole Fluid

45

40

35

30 >.

"33

25

q>

20

I S

15

10

5

-5

-5

0

5

10

15

20

25

30

Apparent Limestone Porosity, 4a(%)

6-16 81

35

40

45

WESTERN ATLAS

Compensated Neutron Borehole Size and Salinity Correction (for Series 2420 CN Log)

250,000 ppm NaCI Equivalent Borehole Fluid

5

10

15

20

25

30

35

40

45

Apparent Limestone Porosity, $a{%)

45

40

250,000 ppm NaCI Equivalent Borehole Fluid

Metric

Borehole

500 mm-

Size

350 mm

150 mm 100 mm

300 mm

200 mm

250 mm

35

30

25

20

15

10

5

0

-5 -5

5

10

15

20

25

30

Apparent Limestone Porosity, $a(e

6-17 82

35

40

45

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log)

0 ppm NaCI Equivalent Borehole Fluid

£

5

10

15

20

25

30

35

40

45

40

45

Apparent Limestone Porosity, 4>a(%)

0 ppm NaCI Equivalent Borehole Fluid

j

5

10

i

15

20

25

30

Apparent Limestone Porosity, 4>a(%)

6-18 83

35

WESTERN ATLAS

Compensated Neutron Borehole Size and Salinity Correction

ATLAS

(for Series 2435 CN Log)

50,000 ppm NaCI Equivalent Borehole Fluid

-5

-5

0

5

10

15

20

25

30

35

40

45

Apparent Limestone Porosity, 4>a(%)

50,000 ppm NaCI Equivalent Borehole Fluid

45

40

/^%K

Metric

35

Borehole

f 25

Size

E

£ «

1 E

i

20

15

10 o

O

-5 -5

0

5

10

15

20

25

30

Apparent Limestone Porosity, |a(

6-19 84

40

45

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log)

100,000 ppm NaCI Equivalent Borehole Fluid 45

40

English

Borehole Size

10

-5

-5

10

0

15

20

25

30

35

40

Apparent Limestone Porosity,

100,000 ppm NaCI Equivalent Borehole Fluid 45

40

Metric

35

10

15

20

25

30

35

Apparent Limestone Porosity, 4a(%)

6-20 85

40

45

WESTERN ATLAS

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log)

150,000 ppm NaCI Equivalent Borehole Fluid

45

40

English

Borehole Size

-5

0

5

10

15

20

25

30

35

40

45

40

45

Apparent Limestone Porosity, $a(%)

45

40

150,000 ppm NaCI Equivalent Borehole Fluid

Metric

35

8

30

25

&

E '3 ■a

o

O

5

10

15

20

25

30

Apparent Limestone Porosity, +a(%)

6-21 86

35

WESTERN ATLAS

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log)

200,000 ppm NaCI Equivalent Borehole Fluid

English

Borehole Size

-5

0

5

10

15

20

25

30

35

40

45

40

45

Apparent Limestone Porosity, +a(%)

45

40

200,000 ppm NaCI Equivalent Borehole Fluid

Metric

35

5

10

15

20

25

30

Apparent Limestone Porosity, $a(%)

6-22 87

35

ISil

WESTERN ATLAS

Compensated Neutron Borehole Size and Salinity Correction (for Series 2435 CN Log)

250,000 ppm NaCI Equivalent Borehole Fluid 45

40

35

§

30

f

25

I

20

I

15 10

-5 -5

0

5

10

15

20

25

30

35

40

45

Apparent Limestone Porosity, <|>a(%)

250,000 ppm NaCI Equivalent Borehole Fluid

300 mm mm

500 mm

5

10

j

i

15

20

25

30

Apparent Limestone Porosity, $a(°/o)

6-23 88

35

40

45

WESTERN ATLAS

iSil

WESTERN

ATLAS

Sidewall Neutron Mudcake Correction

Corrected Limestone Porosity, $cor (%)

10

15

20

25

30

35

^l 3 1/4 -

For

9 5

Mudcake ^ 1/2 S 3/4

For

£ 1400 kg/m3

.4 kg/cm3 j=

c

5 10

15

20

35

25

f-

Mudcake

•§

Stdewalt Neutron Limestone Porosity, ^swn^)

English:

<J)cor = (0.0O088hmc + 0.00326)2SWN + ( - 0.26126hmc + 0.901255)
" °'Olhmc + 0.

(t>cor = (0.000034h

Corrected Limestone Porosity, <|>cor (%) 10

/

15

20

25

30

E

35

<§■ 3

g

•=

For 2500 kg/m^

Mudcake

10

15

20

25

Sidewall Neutron Limestone Porosity, $swn(%)

English:

<)>cor = (0.00853hmc - 0.00041)<»2SWN + ( - 0.245hmc +

- (3.385hmc + 0.1105)

Metric:

(t>cor = (0.00033hmc - 0.00041)^SWN + ( - 0.01hmc + 1.016M»SWN - (0.125hmc + 0.1105)

f

6-24 89

Compensated Neutron Mudcake, Casing, and Cement Correction

WESTERN ATLAS

(for Series 2420 CN Log) ^

Mudcake Correction

Mudcake Correction <j>cor =

x 0.25 (<)>a - 0.225) +

5

10

15

20

25

30

35

40

Apparent Limestone Porosity, | (%)

Casing and Cement Correction 40 Open Hole-

7-in . 20-lb Casing in 8-3/4-in. Borehole

35 8

Casing and Cement Correction

0.272ln Steel

#

0.875in. Comont

30

7-in., 20-lb casing in 8-3/4-in. borehole

5-1/2-ln., 17-lb Casing In 7-7(8-ln. Borehole,

*cor = a " 3

0.304-tn. Steel

1.19-ln. Cement

5-1/2-in., 17-lb casing in 7-7/8-in. borehole

*cor = a " 4 5-1/2-in., 17-lb casing in 8-3/4-in. borehole

cor = a " 5

5-1/2-ln., 17-lb Casing In 8-3/4in. Botehola

0304ln. steel 1 625 In Cement

5

10

15

20

I

I

I

25

30

35

40

Apparent Limestone Porosity, $a( ^

6-25 90

WESTERN ATLAS

Formation Salinity and Mud Weight Correction

(for Series 2420 CN Log)

Formation Salinity Effect

Formation Salinity 0 ppm NaCI,

t'cor = <>a 100,000 ppm NaCI,

a

Fresh Water

250,000 ppm NaCI,

<|>cor = 1.105 ^

100,000 ppm NaCI

250,000 ppm NaCI

0

5

10

15

20

25

30

35

Apparent Limestone Porosity, $a(%)

Mud Weight Correction

Mud Weight Correction

No correction when <)>a < 20% For 8 lb/gal, «J»cor = $a For ^ > 20%, MW > 8 Ib/gal

|>cor

(0.386 log MW + 0.651)

x ((J>a - 20)

5

10

15

20

25

30

35

+ 20

40

Apparent Limestone Porosity, ♦_(%)

Note: Formation salinity is not considered to be an environmental correction. Rather, it should be used for interpretive purposes along with R^ Sw, lithology, etc.

6-26 91

Compensated Neutron Mud Weight Correction (for Series 2435 CN Log)

Freshwater Barite Muds

5

10

15

20

25

30

35

40

Apparent Limestone Porosity, $a (%)

Freshwater Barite Muds

Fresh Water

5

10

15

20

25

30

Apparent Limestone Porosity, <$a (%)

6-27 92

35

40

WESTERN ATLAS

Compensated Neutron Mud Weight Correction

(for Series 2435 CN Log)

Freshwater Non-Barite Muds 40

1 35 J

30

2

25

c

20

5

15

a

10

£

5

10

15

20

25

30

35

40

35

40

Apparent Limestone Porosity, 4a (%)

Freshwater Non-Barite Muds 40

I 35

J

30

8

25

2

20

I

15

I

10 5

5

10

15

20

25

30

Apparent Limestone Porosity, |a (%)

6-28 93

WESTERN

ATLAS

ISil

WESTERN ATLAS

Compensated Neutron Standoff Correction (for Series 2418 CN Log)

Freshwater Borehole

English -2

§

"4

o

O

-6

Standoff CO

t

-8

s. -10

-12

0

2

4

6

8

10

12

14

16

18

20

400

450

500

Borehole Size (in.)

Freshwater Borehole 5 mm

Metric -2

£.

-4

-6

Standoff

-8

-10

-12

0

50

100

150

200

250

300

Borehole Size (mm)

6-29 94

350

Bit

WESTERN ATLAS

Compensated Neutron StandotT Correction

(for Series 2420 CN Log)

0

2

4

6

8

10

12

14

16

18

20

400

450

500

Borehole Size (in.)

Freshwater Borehole

5 mm

£ -10

-12

50

100

150

200

250

300

Borehole Size (mm)

6-30 95

350

ESifl

WESTERN ATLAS

Compensated Neutron Standoff Correction (for Series 2435 CN Log)

Freshwater Borehole

English

0-25 in.

-2

-4

i

S

a

-6

o

O

% ■o

-8

2

CO

>.

-10

-12

-14

-16

I

I

6

8

10

12

14

16

18

20

Borehole Size (in.)

Freshwater Borehole

5 mm

Metric -2

-4

.2

-6

-8

CO

Standoff -10

-14

-16

I 50

100

150

J

I

J_

j

I

J_

200

250

300

350

400

450

Borehole Size (mm)

6-31 96

500

Compensated Neutron Log Temperature and Pressure Correction

Temperature Correction

0

5

10

15

20

25

30

35

40

Apparent Limestone Porosity, $a (p.u.)

Pressure Correction 40

14.7 psi(100 kPa).

35

30 25

10,000 psi (=70,000 kPa).

20.000 psi (=140,000 kPa).

20

15

g o

O

10

5

0

5

10

15

20

25

30

35

40

Apparent Limestone Porosity, <j>a (p.u.)

The above temperature and pressure corrections apply to all Compensated Neutron tools.

6-32 97

Bll

WESTERN ATLAS

ATLAS

Compensated Neutron Combined Lithology and Absorber Effect Correction

Absorber Effect 50 45 40 35 2 o

0.

30

25

s 20

I%

15

5

o

10

-5

0

5

10

15

20

25

30

35

Apparent Limestone Porosity, $a (%)

Combined Lithology & Absorber Effect

1

Apparent Limestone Porosity,
6-33 98

40

45

Mudcake Corrections for Compensated Neutron

Caicite and Barite Mudcake Effect

Thickness 0.00 in. (0 mm)

0.25 in. (6 mm) o

o

£L

"8

I

O

15

20

25

Apparent Porosity, <|>a (%)

Mudcake Correction for Hematite Mud 5.0

2.5

| o

O

-2.5

-5.0

10

20

30

Apparent Porosity (p.u.)

6-34 99

40

50

ATLAS

WESTERN ATLAS

Mud Weight Corrections for Compensated Neutron

40

35

30

25

20

15

10

5

0

10

15

20

25

30

35

Apparent Limestone Porosity, a (%)

Hematite Mudcake Correction

Thickness

0.00 in. {0 mm) ■Ei 0.25 in. (6 mm) 0.50 in. (13 mm);

if 0.75 in. (19mm)ij 1.00 in. (25 mm);

20

25

Apparent Porosity, $ (%)

6-35 100

30

35

40

KSifl

ERM ATLAS

Compensated Neutron Lithology Effect (for Series 2420 CN Log and Sidewall Neutron)

10

15

20

25

Apparent Limestone Porosity, |a (%)

Compensated Neutron (for Series 2420 CN Log) Dolomite: 0cor = <J>a - 6, when 4>a > 12;

*cor = 0.0476 a2 - O.O714 0a Sandstone: <|)

cor

+ 4

Sidewal) Neutron

Dolomite:

cor = 0.00384 $a2 + 0.824 <|>a - 1.240

Sandstone:

<J>cor =

-0.00311 <|>a2 + 1.106 a + 2.696

6-36 101

30

35

40

Compensated Neutron Lithology Effect (for Series 2435 CN Log)

Apparent Limestone Porosity,

102

WESTERN ATIA8

WESTERN ATLAS

Formation Salinity Effect

(for Series 2435 CN Log) ^k Sandstone Formation

Limestone Formation 35

w

30

25

I

20

C

I

15

E

GO

10

5

10

15

20

25

30

35

5

10

Sandstone Porosity, 4 (%)

15

20

25

30

Limestone Porosity, k (%)

Dolomite Formation

10

15

20

25

30

35

Dolomite Porosity, j (%)

Note: Formation salinity is not considered to be an environmental correction. Rather, it should be used for interpretive purposes along with Rw, Sw, lithology, etc.

6-39 104

35

Porosity and Lithology Determination from Compensated

Density and Compensated Neutron Log (for Series 2420 CN Log)

105

WESTERN ATLAS

Porosity and Lithology Determination from Compensated Density and Compensated Neutron Log (for Series 2420 CN Log)

106

WES1

ATLAS

Porosity and Lithology Determination from

Compensated Density and Compensated Neutron Log (for Series 2435 CN Log)

107

WESTERN ATLAS

WESTERN ATLAS

Porosity and Lithology Determination from Compensated Density and Compensated Neutron Log (for Series 2435 CN Log)

p. = 1.1 g/cm3 or Mg/m3 :2.65

40-

:2.71 40-

3535-

40-

30-

30-

35-

25"

25-

30-

20-

20-

15-

2515-

10-

20ffl

105"

155-

0-I 10SS

oNote: LS

Follow lines according to

5 -

rock mixture as defined by Limestone and Dolomite Sandstone and Limestone Sandstone and Dolomite

0 J

*a

DOL

■t-jjt Anhydrite

0

10

20

30

40

Compensated Neutron Apparent Limestone Porosity (%) I

0

i

i

i

i

i

|

|

i

i

5 10 15 20 25 30 35 40 45 Compensated Neutron Apparent Sandstone Porosity (%)

6-43 108

Porosity and Lithology Determination from

WESTERN ATLAS

Compensated Density and Sidewall Neutron Log

1.9

40-

.2.71

2.0

40"

35• 2.86 35-

40"

2.1

3030"

2.2

35-

25-

3

25-

2.3

30-

20-

.o

2025-

15-

2.4 IB c

1510-

a

20-

m

2.5

10-

5-

15-

2.6 5010-

SS

2.7

0>a

LS

2.8

0-

DOL

2.9

3.0

- 10

0

10

20

30

40

Sidewall Neutron Apparent Limestone Porosity (%) i

i

I

I

i

|

i

i

(

0

5

10

15

20

25

30

35

40

Sidewall Neutron Apparent Sandstone Porosity (%)

6-44 109

50

Porosity and Lithology Determination from Compensated Density and Sidewall Neutron Log

110

Porosity and Lithology Determination from

ATLAS

Compensated Neutron Log and BHC Acoustilog for Series 2420 CN Log)

= 55.5

110

40-i

"3 360

40"

340

35-

40 -i

100

320

353035-

300

90

302530-

280 20-

25-

80

25-

15-

20-

260

ID

i= o

P

240

20-

10-

15-

3

a.

w

220

15-

5-

10200

60

10-

0J

Note:

5-

180

Follow lines according to

SS

rock mixture as defined by 5-

50

Limestone and Dolomite Sandstone and Limestone Sandstone and Dolomite

Anhydrit

160

0-

LS 140 DOL Acoustic porosity computed from

40

-10

0

10

20

30

40

Compensated Neutron Apparent Limestone Porosity (%)

Wyllie-Rose.

0

5

10

15

20

25

30

35

Compensated Neutron Apparent Sandstone Porosity (%)

6-46 111

40

50

o

I

1

Q.

CO

KSlfl

WESTERN ATLAS

Porosity and Lithology Determination from

Compensated Neutron Log and BHC Acoustilog (for Series 2420 CN Log)

q 360

Atma = 55.5 40 -i 47.5

4035-

-

340

-

320

-

260

43.5 40-

35-

3035-

25-

3030-

20-

25-

25-

s a

15-

20-

20-

10-

15-

CO

15-

5-

10-

ID 05-

SS

0LS -

DOL

0

Acoustic porosity computed from

10

20

30

40

Compensated Neutron Apparent Limestone Porosity (%)

Wyllie-Rose

0

5

10

15

20

25

30

35

Compensated Neutron Apparent Sandstone Porosity (%)

6-47 112

40

140

WESTERN AT1A8

Porosity and Lithology Determination from

BHC Acoustilog and Compensated Neutron Log (for Series 2435 CN Log)

55.5

40 -I

360

-

340

-

320

At. = 189 fiS/ft or 620 ^s/m

A'ma - 475 40-i 35-

=1

40-

3530-

35

25-

30-

30"

20-

2525-

15 -

20.9

20"

£

70

15 " CO

15"

5-

10-

10-

0 J 5 -

SS 5-

Note: Follow lines according to rock mixture as defined by Limestone and Dolomite

0-I

«

Sandstone and Limestone Sandstone and Dolomite

i~—•

0-I ♦a

-

DOL

Acoustic porosity computed from

Wyllie-Rose.

~10

0

10

20

30

40

Compensated Neutron Apparent Limestone Porosity (%) I

1

1

1

1

0

5

10

15

20

''■■

25

30

35

40

Compensated Neutron Apparent Sandstone Porosity (%)

6-48 113

50

140

WESTERN ATLAS

Porosity and Lithology Determination from

BHC Acoustilog and Compensated Neutron Log (for Series 2435 CN Log)

110

, = 55.5

360

40 -i

= 47.5

340 435

35 -

100 320

30 -

300 90 25 -

280

20-

80

260

l=

15 -

o

o

1

Spec

■i

10-

240 |

o

70 220

5 200 60

0180

ss

Note:

Follow lines according to 50

rock mixture as defined by Limestone and Dolomite

Anhydrite

160

Sandstone and Limestone Sandstone and Dolomite

140 DOL Acoustic porosity computed from

1

40

-10

1

0

10

I

1

1

20

30

40

Compensated Neutron Apparent Limestone Porosity (%)

Wyllie-Rose.

II

0

5

10

15

20

25

30

35

40

Compensated Neutron Apparent Sandstone Porosity (%)

6-49 114

50

w

Porosity and Lithology Determination from

Sidewall Neutron Log and BHC Acoustilog

115

Porosity and Lithology Determination from Sidewall Neutron Log and BHC Acoustilog

116

WESTERN ATLAS

WESTERN

Porosity and Lithology Determination from

ATLAS

Compensated Density and BHC Acoustilog

Specific Acoustic Time, 150

1.9

200 I

■ '

'

l

•

■

■

250

l

14 '

300 ' I

' ■

Sylvlte

2.65

40-1

2.0

At, = 189 MS/ft or 620

40-1

Pma = 2-86 35-

350

' '

pf = 1.0 g/cm3 or Mg/m3

Pma - 271

35-

' I '

2.1

40 -i

30-

30-

35-

2.2

25"

2530-

2.3

20-

20-

25-

15"

1510-

20-

105-

152.6 5-

0 J 10SS

2.7

0-

LS

5-

2.8

0-

DOL

2.9

• Gabbro

3.0 40

50

60

70

80

Specific Acoustic Time, At

6-52 117

90

100

110

KSil

WESTERN ATLAS

Porosity vs. Formation Facfor

50

100

300

500

1000

2000

5000

10,000

Formation Resistivity Factor, F

This chart provides a variety of graphic solutions relating porosity to fonnaiion resistivity factor. Actual measured data can be plotted to construct the best solution for a given area. Alternatively, the cementation factor (m) can be estimated as follows: Very slightly cemented, 1.4 to 1.6 Slightly cemented, 1.6 to 1.8

Moderately cemented, 1.8 to 2.0 Highly cemented sands, carbonates,

> 2.0

Hard Formations:

F = l/ifi™ Low c|> non-fractured carbonates (Shell Oil) m = 1.87 + 0.019/* where Soft Formations: F =

0.62

*

or

F =

0.81

2.15

6-53 118

WESTERN ATLAS

Mineral Identification by M-N Crossplot (using Series 2420 CN Log)

1.3

' Salt

M

*lvma = 19.500 Ws or 5945 m/s)

Limestone^ /'Sandstone ' 'M = 18,000 ft/s or 5488 m/s)

:

O= Fresh Mud. p, = 1.0g/cm3. At, = 189^s/ft

p,= I.OMg/m3, At,-620MS/m

Salt Mud, p, = 1.1 g/cm3, At, = 185 ps/ft p, = 1.1 Mg/m3, At, = 607 /

I

0.3

0.4

0.5

i

i

0.6

0.7

0.8

ii

0.9

1.0

N

English or metric (for pf in g/cm3 or Mg/m3):

N

1 " P\>~ Pf

Metric (for At in

English (for At in us/ft): M

/ Atf - At \

= 0.01 ( -2

M = 0.003048

\ Pb " Pf /

6-54 119

Atf - At

i

1.1

Mineral Identification by M-N Crossplot (using Series 2435 CN Log)

120

WESTERN

Mineral Identification by M-N Crossplot

ATLAS

(Sidewall Neutron Log)

M

0.4

0.3

0.5

0.6

0.7

0.8

0.9

1.0

1.1

N

English or metric (for pf in g/cm3 or Mg/m3):

English (for At in ^s/ft):

Metric (for At in pis/m):

/ Atr - At \

M = 0.01 ( ^

)

M = 0.003048

\ Pb ~ P( )

6-56 121

/Atf-At\

\Pb~Pf )

Mineral Identification Plot

WESTERN ATLAS

Pmaavs-Atmaa

100

120

140

I

2.0

I

160

'

180 I

I

r

200 \

T

220 I

T

240 I

2.1

2.2

2.3

2.4

o

3

2.6

2.7

2.8

2.9

3.0

3.1

30

40

50

60

70

4tma>s/ft)

_ Plog ~ ^D/N Pi

At maa

1 -0D/N where, = density/neutron crossplot porosity

$a/n = acoustic/neutron crossplot porosity

6-67 122

~ <)>A/N

WESTERN ATLAS

Porosity and Lithology Determination from Compensated Z-Densilog

Freshwater-filled Borehole, pf = 1.0 g/cm3 or Mg/m3

I 6

1=

I s

2.7

Note: 2.8

Follow lines according to rock mixture as defined by

Sandstone and Dolomite . Limestone and Dolomite > Sandstone and Limestone

! 3.0

I

12

3

4

Photoelectric Cross Section, Pe (barns/electron)

6-58 123

5

Porosity and Lithology Determination from Compensated Z-Densilog

Saltwater-filled Borehole, pf = 1.1 g/cm3 or Mg/m3 1.8

I Q

9.5 —i

— —

Note: Follow lines according to

— rock mixture as defined by Sandstone and Dolomite Limestone and Dolomite Sandstone and Limestone

—I—I—[—i—■

'

~ --.-T-r—"-r—;-j—

12

3

Photoelectric Cross Section, P

6-59 124

4

(barns/electron)

RSil

WESTERN

ATLAS

1511 Matrix Identification Plot

18

Heavy—L)

16

■5--

I

Minerals

14

CO

12 z> o

1 CO

10

o

I

I Q. Q.

<

3.1

2.9

3.0

2.8

2.7

2.6

25

2.4

2.3

Apparent Matrix Grain Density, p aa(g/cm3 or Mg/m3) - (» x Uf)

Uma, =

where,
pf = 1.0 g/cm3 (fresh water) — 1.1 g/cm3 (salt water)

Uf - 0.398 barns/cm3 (fresh water) = 1.36 barns/cm3 (salt water)

The Matrix Identification Plot can be used to determine the component matrix lithology using the apparent matrix grain density and the apparent matrix volumetric cross section. Charts can also be constructed for rock and mineral mixes.

6-60 125

2.2

WESTERN ATLAS

Porosity Correction for Gypsum Infilling

75

70

fes W

I 60

55

Si o

50

45 Dolomite

40 3.0

I

2.9

2.8

2.7

2.4

2.3

Apparent Matrix Grain Density, p

2.6

2.5

(g/cm3)

maa

2.2

2.1

2.0

The Permian Basin (west Texas and New Mexico, U.S.A.) has a particular interpretation problem caused by gypsum

infilling. The empirically-based chart presented assumes a 40% reduction in acoustic-derived porosity due to the presence of vuggy pores in dolomite. Estimates of gypsum

infilling can be made by comparing At against apparent matrix density (from pb and CN crossplot). A gypsumcorrected porosity value can then be determined.

NOTE OF CAUTION: Empirically based charts for local usage can vary considerably from one field to another within the same geological horizon, and also from one geological formation to another.

^

6-61 126

KM

WESTERN

Estimation of Porosity

ATLAS

in Hydrocarbon - Bearing Formations

:%) 0 Compensated Neutron

Sidewall Neutron

To obtain a good approximation, including excavation effect (0.22 <j)N,

+ 0.78 $D (for Compensated Neutron)

(1 + 0.14 Shr)

(0.3
(for Sidewall Neutron)

where.

= - 0, jl - [1/(1 +0.14 Shr)]

Example Given: $N%

=

lO^o, iQD_

= 3O°/o, Shr = 40% for Compensated Neutron

Determine: ty, 6, = 25.6%, &i> =

-

1.4%, $ = 24.2%

6-62 127

-1

-2

-3

-4

-5

-6

WESTERN ATLAS

Estimation of Hydrocarbon Density in Clean Formation

Compensated Neutron

Sidewall Neutron

1.0 0.9 0.8 0.7 0.6

**<*>< 0.5 -

.0.5 0.4

0.3

0.1 •

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0

Hydrocarbon Density, ph

0.1

0.2

0.3

To obtain a good approximation, including excavation effect

Ph=

(for Compensated Neutron)

Shr (2.67 + 0.75 <J>Nco/0Dcor) Shr P." + 0-72 Nco/Vor)

Ph

0.4

0.5

0.6

Hydrocarbon Density, ph

Shr (1.67 + 0.75 +Nco/«f>Dcor)

(for Sidewall Neutron)

where,

" v sh

1>Dcor = I'D - Vsh X fDsh Example Given: <(>Ncor = 10%, 0Dcor = 30%, Shr = 40% for Compensated Neutron

Determine: ph; N(:o/Dcor = 0-33, Ph = 0.15

6-63 128

0.7

0.8

WESTERN

ATLAS

Estimation of Gas Density at Reservoir Conditions

g (g/cm3)

Typical Values for ph with Respect to:

Oil ~ 0.55 (High API°) to 0.95 (Low APIC Condensate - 0.25 to 0.60

Gas-0.15 to 0.30

6-64 129

WESTERN ATLAS

Induction or Laterolog — Deciding Which Tool Should be the Most Effective and Reliable

30

20

Induction devices are preferred.

15

10 8.0 6.0 5.0

Generally, when FtyRm < 3000. induction devices have preference.

4.0

3.0

1 2.0 Above the dashed line and to the right of appropriate Rw values, select both logs.

1.5

1.0

Dual Laterolog devices

0.8

are preferred.

0.6

0.5 0.4

Generally, when R|/Rm > 8000,

0.3

dual laterologs have preference.

0.2

0.15 35

I

30

25

20

15

10

Porosity (%)

Induction devices were first designed for logging in oil-based mud conditions, a situation where laterolog devices do not work. Induction systems also work in empty or gas-filled boreholes, another condition that eliminates the use of electrode systems.

Shallow, ground conductance can seriously affect induction measurements in shallow wells, and laterologs become the preferred device. Laterologs are also preferred as the resistivity measure ment in reservoirs containing high concentrations of conductive minerals such as pyrite (FeS->). Nevertheless, in water-based drilling fluids, the problem of deciding on induction or laterolog tools requires a sense of the following four conditions: • In-situ formation resistivities (R, or Ro)

• The formation water salinities (Rw) at formation temperature • The resistivity of the drilling fluid (Rm) at formation temperature • The resistivity of the mud filtrate (Rmf) at formation temperature The chart above attempts to clarify which tool is preferred, but note that "gray areas" are still

found, a situation in which both devices are recommended. As a "rule-of-thumb." induction is preferred when Rmf/Rw > 2.5 and Rt/Rm < 3,000. Dual Laterolog devices are preferred in highresistivity formations (> 200 ohm-m and when R,/Rm > 8,000), salt-based drilling fluids, and especially when Rmf/Rw approaches or becomes less than unity.

7-1 131

K5U

WESTERN ATLAS

Borehole Size Correction (for Series 811 Induction Log)

IS

14

13

12

~

11

F

1°

£

3

2 D

-10

-15

5

-5

10

15

Radial Geometric Factor (x 1000)

-20

-30

-40

-50

-60

■70 -70

—|— ■80 -80

-90

-100

-110

-120

-130

-140

-150

Signal tram Hole (mmho/m]

Example

Given: Borehole diameter = HI.5 in.; standoff = 2.5 in.; R,n = 0.5

R]l = 10 Q-m

Determine: Signal from hole - -7 mmho/m = l,000/l()iim= I00 mmho/m = 100 mmlui/ni -(-7 mmho/m) - 107 mmho/m

R1Lcor = 1,0(10/110 mmho/m = 9.3 il-\\\

7-2

Borehole correction = (mmho/ra)

Radial Geometrical Factor (x 1,000) Mud Rc-islivily |Rmj

WESTERN

Borehole Size Correction

ATLAS

(for Series 811 Induction Log)

24

16

14 □

n

a

5

12

-25

-20

-15

5

-10

10

15

Radial Geometric Facior (x 1000)


^

>

J>*

i

i

i

i

-50

i

n

i

i

-100

i

i

i

i

i

f

-150

-200

Signal from Hole (mmho/m)

Example

Given: Borehole diameter - 10.5 in.; standoff = 2.5 in.; Rm = 0.5 Qnv. Ril = 10 Determine: Signal from hole = -7 mmho/m

O-m= lOOmmho/m

BorehoJe

Qlco = 10(J mmho/ni -(-7 mmho/m) - KJ7 mmhp/m JO mmho/m = 9.3 Qm

7-3 133

(inniho/nij

Radial Geomeirical Factor (x 1,000)

Mud Resistivity (Km)

WESTERN ATLAS

Borehole Size Correction (tor Series 814 Induction Log)

5

in

ie

Radial Geometric Factor fx 1000)

-60

-70

-90

-no

-120

-130

Signal from Hole (mmho/m)

Example

Given: Borehole diamcicr = 10 in.: standoff = 1,5 in.; Rm = 0.I £2m; Ril= Determine: Signal from hole = -13 minhu/m Cil= 1,000/10 Q-m = lOOmmlio/m C|Lcor = 100 minJio/m -(-13 inmho/m) =113 mmho/rn

RlLcor = 1 .OCX)/125 mmho/m = 8.8 n m

7-4 134

correclion

(mraJio/m)

=

I Radial Geometrical Factor (x 1,000) V

Mud Ke-sistivity (RmJ

BSil

WESTERN ATLAS

Borehole Size Correction (for Series 814 Induction Log)

24

22

18

16

14

12

10

-25

-20

-10

-15

■5

5

10

15

20

Radial Geometric Factor (x 100Q)

1 ►50

I 0

I -10

I -20

I -30

I -40

I -50

I -60

I -70

I -80

I -90

I -100

I -110

I -120

I -130

1 -140

I -150

I -160

/„ ,. , -.

.

I -170

I -180

r^ -190

Signal from Hole (mmho/m)

Example

Given: Boreliok diiuncier = 10 in.: siaiidoff = 1.5 in.; Rm = (1.1 Sim: Rjl= lOii-m

Determine: Signal from hole »-13 inmho/m C\L= I.000/I0i2.m= 100 mmho/m C\\

= 100 mmho/m -(-13 minho/m)= 11.1 mmlio/m

R1Lcor = 1.000/125 mmho/m = 8.8 Cim

Borehole comcuoD

(mmhu/ml

7-5 135

=

I

\

, ,-

icior i\ 1,000)

Mud Resistivity

WESTERN

Borehole Size Correction

ATLAS

(tor Series 815-818-809 Induction Log)

5

10

15

Radial Geometric Factor (x 1000]

►30

+20

-10

0

-10

-20

-30

-40

-50

-60

■90

-70

-100

-110

-120

-130

Signal from Hole (mmho'm)

Example

Given: BfflE&olediameter = 11.5 in.is(andoff=2in.;Rm = O.5£2m; R[[. = lOii-m Determine: Signal from hole = -6.4 ininho/m

Ch,= 1.000/l0Jl-rn = lOOminho/m C[[

= lOOmmho/rn -(-6.4 mmho/tn) = 106,4 mmlio/m

R[l^)r = i.0(X)/l 10 inmlm/m = 9.4 il-m

corrcclion

(nimho/m)

7-6

Radial Geometrical R Mud Resistivity (Rm)

1.000)

nsai

WESTERN ATLAS

Borehole Size Correction

(for Series 815-818-809 Induction Log)

24

22

IB

IB

5

12

10

■25

-15

-20

s

■10

ia

15

Radial Geometric Factor (x 1000]

+50 +40 +30 +20 +16

0

-10

-20 -30 -40

-50

-60

-70

-SO

i—i r i—i—r -90 -100-110 -120;-130-t40-1S0-160-170-180-190

Signal from Hals (mmho/m}

Example

Given: Borehole diameter = 11.5 in.; standoff = 2 in.; Rm =S.$®-m;RlL = lQO-|» Determine: Signal from hole = -64 minho/m Cji. = 1,000/10 n-m = 100 mmho/m

Cil

= 100 mmho/m -(-6.4 mmho/m) = 1064mmho/m

RlLcur = 1.000/110 mmho/m = 9 A Urn

Radial Geometrical Fatitir (X 1.0(X» (ninllio/m)

7-7 137

Mud Resistivity
RSii

Borehole Size Correction for Deep Induction Log

WESTERN ATLAS

(tor Series 1503/1507 DIFL/DPIL)

4

5

6

Radial Geometric Factor (x 1000)

40

55

30

25

20

15

Signal Irom Hols (mmho/m)

Example

Given: Borehole diameter = 14 in.; Rm = 0.1 Hm; standoff's 1.5 in.; Rtld= lOQm Determine: Signal from Hole = 16 inniho/m

Cil= 1,000/10Q*mm lOOmmho/m

'-"-cor= ""^ min!l(^m -16 nimho/m = 84 mmho/m r" ' ■000/80 mmho/m =11.9 Q-m

Borehole COITCtliOll

(iTiniho/m)

7-8 138

nil Geomeirical FaetiH I* 1,000; Mud Resistivity (Rm)

WESTERN ATLAS

Borehole Size Correction tor Deep Induction Log (tor Series 1503/1507 DIFL/DIML)

24

22

—

20

1G

14 3

1

12

10

10

■10

15

fladial Gecmeinc Factor (i 1000)

150

140

Signal (rom Hole (mmho/m)

Example Given: Borehole diameter* 14 in.; Rm = 0.1 Q-m; standoff = 1.5 in.; RjLD"1 Determine: Signal from Hole* 16 mnvho/m Cii. = 1.000/10 n-m = 100 mmho/m CiL-[ir- '00 minho/m -16 inmho/m = 84 mmho/m

^r = 1.000/80 mmho/in =11.9 Q-m

R:idi;il Guomtlrica] Faclor [\ l.000)\ (nimhn/m)

7-9 139

Mud Resislivitj (Rm)

/

Borehole Size Correction for Medium Induction Log

WESTERN ATLAS

(for Series 1503/1507 DIFL/DPIL)

-1

9

10

11

15

Radial Geometric Factor fx 1000)

SO

40

20

10

Signal Iram Hole (mmho/m)

Example

This chan provides a method for determining how much of ihc recorded signal is due to the borehole. Given: Borehole diameter" ]() in.; Rm = 0.1 il-m: standoffs Determine: .Signal from Hole ~ 21 mmho/m

.5 in. Borehole

correction jinmho/m)

7-10 141)

Radial Oeomeiricfll Facior (,\ l.QOOj Mud Roslsiiviiy (R,o)

■an

WESTERN

Borehole Size Correction for Medium Induction Log

ATLAS

(for Series 1503/1507 DIFL/DPIL}

24

22

20

!B

12

10

-18

-16

-14

-12

-10

-a

6

-6-1

8

10

12

14

16

1B

Radial Geamelric Factor (* 1000)

I

I

I

I

i

180

160

140

120

100

80

60

40

Signal from Hole (mmho/m)

Example

This chart provides a method for determining how much of the recorded signal is due (o die borehole.

Given: Borehole diameter = 10 in.; Rm = 0.1 Urn; standoff « 1.5 in. Determine: Signal from Hole = 27 mmho/m Borehole <:orrci;tiun

(mmho/m)

7-11 141

itedlal Geometricid Futi(jr(s 1,000) Mud Resistivity (Rra)

Bed Thickness Correction for Deep Induction Log

20

16 ft and 12 ft (4-5 m)

7 ft (2 m)^ 10 8 ft

10 ft (3 m)

R.-1

5

? 4 oi

3

2

0.5

1.0

2

3

4

5

10

0.5

20

0.5

1.0

2

3

4

5

10

20

?

SI

10

7-12 142

15

20

25

■Zil

WESTERN ATLAS

Bed Thickness Correction for Deep Induction Log

100

100

6 ft (i ;s my

Rs = 5

80

5 ft (1.5 m)

E" 60

|-

80

60

SL

a

of

J

40

40

20

20

20

40

60

80

100

20

40

80

100

100

: S ft or 6 ft (1.5-1.8 m)

80

Rs = 20

60

a 40

20

20

40

60

80

100

100

7-13 143

Bii

WESTERN AT1AS

Bed Thickness Correction for Dual Laterolog

Bed Thickness Correction for Dual Laterolog (Deep)

2.4

Conductive Beds R,/Rm

500 2.0

20

Resistive Beds R^R,,, = 20 100

1.6

1.2

0.8

0.4

3

456789 10

20

30

40

50

60 70 8090100

Bed Thickness (ft)

0.5

1

2

3

4

5

10

15

20

30

Bed Thickness (m)

Bed Thickness Correction for Dual Laterolog (Shallow) 2.4

500

Conductive Beds

100 2.0

Resistive Beds

=120

1.6

1.2

0.8

0.005'

I

0.4

3

4

5

I

6789 10 Bed Thickness (ft)

7-14 144

20

30

40

50

60 70 8090100

Borehole Size Correction for Dual Laterolog (DLL) Deep (for Series 1229 EA/EB K = 0.7998) K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Centered

Thick Beds

100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLD^m) by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value (Rlu)) to determine the corrected log value

7-15 145

Borehole Size Correction for Dual Laterolog (DLL) Deep (for Series 1229 EA/EB K = 0.7998) K = tool calibration factor ("K-factor") in ohm.m/ohm

Tool Eccentered

Thick Beds

100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLD^m) ^y projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value

to determine the corrected log value

'corr

)■

i\

7-16 146

CRN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Deep (for Series 1229 EA/EB K = 0.7998) K = tool calibration factor ("K-factor") in ohnvm/ohm

1.4

Tool Pipe Conveyed

Thick Beds

BHO < 8 in.: 0.5-in. Standoff BHD > 8 in.: 1 5-in. Standoff

1.3

1000

10000

This chart provides a method to correct the log value for the influence of ihe borehole. The chart is entered from the

horizontal axis (RLLD^m^ ^y projecting a Hne upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value (Rjxd) t0 determine the corrected log value (Rj_ld ^

7-17 147

Bil

WESTERN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Shallow (for Series 1229 EA/EB K = 13379) K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Centered

1.4

Thick Beds

Normalized to: 8-in. borehole

1.3

1.2



1.1

£

1

0.9

0.8

)

0.7

0.1

10

100

1000

j

t

f

t

t

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLS^tn) ^v ProJect'"g a 'me upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value (Rljj;) to determine the corrected log value

7-18 148

WESTERN

Borehole Size Correction for Dual Laterolog (DLL) Shallow

ATLAS

(for Series 1229 EA/EB K = 1.3379) K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Eccentered

1.4

Thick Beds

BHD < 8 in.: 0.5-in. Standoff BHDS8in.;1.5-in. Standoff

1.3

1.2

(A

_l

_l

cc o

u

Ui _i

tr.

0.8

0.7

J

1000

I

I

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RlLS^W by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value (Rjxs) t0 determine the corrected log value

7-19 149

WESTERN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Shallow

(for Series 1229 EA/EB K = 1.3379) K = tool calibration factor ("K-factor") in ohm-m/ohm

Tool Pipe Conveyed

1.4

Thick Beds

BHD < 8 in.: 0.5-in. Standoff BHD J 8 in.: 1.5-in. Standoff

1.3

1.2

3

1.1

a

1

0.9

0.8

0.7 0.1

100

10

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLS^m^ by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (R[xs)t0 determine tne corrected log value

/^!\

7-20 150

Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EA/EB K = 0.9029) K = tool calibration factor ("K-factor") in ohmm/ohm

Current Return at 40 ft

Tool Centered

Thick Beds

1000

0.1

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLC/^m) by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the venical axis, which is then multiplied by the actual log value (RLLG) to determine the corrected log value (RLLGcorr).

7-21 151

Bil

Borehole Size Correction for Dual Laterolog (DLL) Groningen

WESTERN ATLAS

(for Series 1229 EA/EB K = 0.9029) K = tool calibration factor ("K-factor") in ohmm/ohm

1.4

Current Return at 40 ft

Tool Eccentered

Thick Beds

BHD < 8 in.: 0.5-tn. Standoff

BHD 2 8 in.: 1.5-in. Standoff 1.3

1.2

1.1

(f1 o

0.9

0.8

0.7

0.1

10

100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RllG^iti) ^y projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rllq) t0 determine lne corrected log value

'corr

7-22 152

Kit

WESTERN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EA/EB K = 0.9029) K = tool calibration factor ("K-factor") in ohm-m/ohm

Current Return at 40 ft

1.4

Tool Pipe Conveyed Thick Beds

BHD < 8 in.: 0.5-in. Standoff BHD > 8 in.: 1.5-in Standoff

1.3

1.2

O

1.1

0.9

0.8

0.7 0.1

100

10

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RlLG^iti) by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value

t0 determine the corrected log value

'corr

7-23 153

)■

WES1

Borehole Size Correction for Dual Laterolog (DLL) Groningen

ATLAS

(for Series 1229 EA/EB K = 0.8765) K = tool calibration factor ("K-factor") in ohmm/ohm

Current Return at 60 ft

Tool Centered

Thick Beds

0.8

0.7

7 nhl/ill, 0.1

I 10

1000

10000

RLLG'Rm

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RllG^W ^v projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value

to determine ^e corrected log value

corr

).

{

7-24 154

Borehole Size Correction for Dual Laterolog (DLL) Groningen

ATLAS

(for Series 1229 EA/EB K = 0.8765) K = tool calibration factor ("K-factor") in ohmm/ohm

Current Return at 60 ft

Tool Eccentered

Thick Beds

1.4

BHD < 8 in.: 0.5-in. Standoff BHD > 8 in.: 1.5-in. Standoff 1.3

1.2

a

1.1

O

3

0.9

0.8

0.7

0.1

10

100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RlLG^iti) ^y projecting a l'ne upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value

Io determine the corrected log value

'corr )■

7-25 155

Borehole Size Correction for Dual Laterolog (DLL) Groningen

WESTERN ATLAS

(for Series 1229 EA/EB K = 0.8765) K = tool calibration factor ("K-factor") in ohmm/ohm

1.4

Current Return at 60 ft

Tool Pipe Conveyed Thick Beds

BHD < 8 in.: 0.5-in. Standoff BHD>8in.:1.5-in. Standoff 1.3

0.8

^

0.7

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLG^m) bv projecting a line upward to the appropriate borehole size curve. From that point, a

line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (R) to determine deti th corrected td log l l (R the value

)).

%,

7-26 156

WESTERN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Deep (for Series 1229 EC K = 0.7939) K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Centered

Thick Beds

1.4 Normalized to:

8-in. borehole

RLLDapp/Rm=100

1.3

Homogeneous medium

1.2

a

1.1

0.9

0.8

0.7 0.1

100

10

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLfV^m^ by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value (Rlld) to determine the corrected log value

'corr

7-27 157

WESTERN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Deep (for Series 1229 EC K = 0.7939)

^

K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Eccentered

1.4

Thick Beds

BHD < 8 in.: 0.5-in. Standoff BHD > 8 in.: 1.5-in. Standoff

1.3

1.2

1.1

0.9

0.8

0.7

0.1

100

10

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLD^m^ ^v projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (RlLD^ to determine the corrected log value

7-28 158

RSil Borehole Size Correction for Dual Laterolog (DLL) Deep

(for Series 1229 EC K = 0.7939) K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Pipe Conveyed

Thick Beds

1.4

1.3

-

1.2

—

3 M tr

1

—

0.9

0.8

—

0.7 0.1

100

10

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLD^m.) ^ projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rlld) to determine the corrected log value

7-29 159

ESil

WESTERN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Shallow (for Series 1229 EC K = 0.9821) K = tool calibration factor ("K-factor") in ohm-m/ohm

Tool Centered

Thick Beds

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLS^m^ ^v projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rlls) to determine the corrected log value

corr

|\

7-30 160

WESTERN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Shallow

(for Series 1229 EC K = 0.9821) K = tool calibration factor ("K-factor") in ohrrvm/ohm

Tool Eccentered

1.4

Thick Beds

BHD < 8 in.: 0.5-in. Standoff BHD > 8 in.: 1.5-in. Standoff

1.3

1.2

0.7 100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the horizontal axis (RLLS^m) by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value

to determine the corrected log value

corr

7-31 161

).

Borehole Size Correction for Dual Laterolog (DLL) Shallow (for Series 1229 EC K = 0.9821) /%

K = tool calibration factor ("K-factor") in ohm-m/ohm

Tool Pipe Conveyed

Thick Beds

^L

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLS^m) ^y projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rll§) to determine ^e corrected log value (Rll<j

)•

|k

7-32 162

Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EC K = 0.8984) K = tool calibration factor ("K-factor") in ohmm/ohm

Current Return at 40 ft 1.4

Tool Centered

Thick Beds

i I I UN Normalized to:

8-in. borehole 1.3

RLLGapp/Rm=100

Homogeneous medium

1.2

0.7 1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLG^m^ by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rllg) t0 determine the corrected log value (RLLGcorr)-

7-33 163

KM

WESTERN ATLAS

Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EC K = 0.8984) K = tool calibration factor ("K-factor") in ohmm/ohm

1.4

Current Return at 40 ft

Tool Pipe Conveyed Thick Beds

BHD < 8 in.: 0.5-in. Standoff BHD > 8 in.: 1.5-in. Standoff 1.3

1.2

0.8

0.7

0.1

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLG^m' by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rllg) t0 ^etermme tne corrected log value

corr

7-34 164

Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EC K = 0.8984) K = tool calibration factor ("K-factor") in ohmm/ohm

Current Return at 40 ft

Tool Eccentered

Thick Beds

1.4

BHD < 8 in.: 0.5-in. Standoff BHD > 8 in.: 1 5-in. Standoff

1.3

1.2

100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RLLG^m) by ProJecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rllg) t0 determine tne corrected log value (RLLGcorp"

7-35 165

Borehole Size Correction for Dual Laterolog (DLL) Groningen (for Series 1229 EC K = 0.8712) K = tool calibration factor ("K-factor") in ohmm/ohm

Current Return at 60 ft

1.4

Tool Centered

Thick Beds

1.3

1.2

C3

3

IT

1.1

1

0.9

0.8

\

0.7

0.1

10

100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the horizontal axis (RllG^W ^v projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value

to determine the corrected log value

'corr

7-36 166

)■

Borehole Size Correction for Dual Laterolog (DLL) Groningen

WESTERN

ATLAS

(for Series 1229 EC K = 0.8712) K = tool calibration factor ("K-factor") in ohmm/ohm

Current Return at 60 ft 1.4

!

!

Tool Eccentered

Thick Beds

i ! I II!

BHD < 8 in.: O.S-in. Standoff BHD > 8 in.: 1.5-in. Standoff

1.3

1.2

a

1.1

o

0.9

0.8

0.7 0.1

10

100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the horizontal axis (Rm^m) ^ projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value (Rllq) t0 determine the corrected log value

/

7-37 167

Borehole Size Correction for Dual Laterolog (DLL) Groningen

WESTERN ATLAS

(for Series 1229 EC K = 0.8712) K = tool calibration factor ("K-factor") in ohmm/ohm

Current Return at 60 ft

Tool Pipe Conveyed Thick Beds

BHD < 8 in.: 0.5-in. Standoff BHD > 8 in.: 1.5-in. Standoff

0.7

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the horizontal axis (RLLG^m^ by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual log value t0 determine the corrected log value l l (R )■ corr

7-38 168

Sffi

Borehole Size Correction for Dual Phase Induction (DPIL) Shallow Focused Log (for Series 1507 XB K = 2.13) K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Centered

Thick Beds

1.5

1.4

—

100C0

0.1

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from

horizontal axis (RsFL/Rm) by projecting a line upward to the appropriate borehole size curve. From that point, a

line is projected to the left to derive a correction factor (RsFLcor/^SFL,) al°ngtne vertical axis, which is then

multiplied by the actual log value (R<jfl) t0 determine the value corrected for borehole signal (RsFLcorP'

7-39 169

Kifl

Borehole Size Correction for Dual Phase Induction (DPIL) Shallow Focused Log

""BBis

(for Series 1507 XB K = 2.13) ^

K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Eccentered

1.5

Thick Beds

BHD < 8 in.: O.S-in. Standoff 1.4

BHD>8in.: 1.5-in. Standoff

1.3

1000

10000

RSFL'Rm

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from

horizontal axis (RsFl/^m) ^v ProJec*ing a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor (RsFLcor/^SFlJ a'on8 ^e vertical axis, which is then multiplied by the actual log value (RsFlJ t0 determine the value corrected for borehole signal (RgpL )■

j

7-40 170

Borehole Size Correction for Dual Induction Focused Log (DIFL) (for Series 1503 XC K = 0.7807) K = tool calibration factor ("K-factor") in ohmm/ohm

Tool Centered

1.5

Thick Beds

Normalized to: 8-in. borehole 1.4

1.3

1.2

5

1.1

0.9

0.8

O.7

0.1

10

100

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RpoC^m) by projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rpoc)t0 determine the corrected log value (Rpoc

7-41 171

„)•

IZifl

Borehole Size Correction for Dual-Induction Focused Log (DIFL) (for Series 1503 XC K = 0.7807)

%

K = tool calibration factor ("K-factor") in ohm-m/ohm

Tool Eccentered

Thick Beds

LL

1

0.7

i-i-L

1000

10000

This chart provides a method to correct the log value for the influence of the borehole. The chart is entered from the

horizontal axis (RpoC^m) bv projecting a line upward to the appropriate borehole size curve. From that point, a line is projected to the left to derive a correction factor along the vertical axis, which is then multiplied by the actual

log value (Rpoc)to determine the corrected log value (RpQC

7-42 172

r^-

Rt from 1229 EA/EB (for Rt > Rxo)

Using Deep (RLld)> Shallow (RLls)> and Rxo

173

WESTERN ATLAS

Rt from 1229 EA/EB (for Rt > R^)

Using Groningen (Rllg)» Shallow (Rlls)' and Rxo Current Return at 40 ft

100 :

10

Is

tr"1

.1

10

.5 □

20

/ R

nLLG ' nLLS

This chan provides a method of obtaining R, from the Dual Laterolog (1229 EA/EB) using Groningen (Rllg^ readings where Rt > Rxo. This chan is developed for the Groningen setup that has the current return spaced at

40 ft. Rxo should be determined from an auxiliary survey such as the Micro Laterolog. Rxo, Rllg- an(* should be corrected for borehole effects before using this chart. An example illustrating the use of this type of chart is given with Chart 7-68.

7-44 174

Rt from 1229 EA/EB (for Tt > Rxo)

Using Groningen (RllG>» Shallow (R^ls)' and Rxo Current Return at 60 ft

175

ATLAS

Rt from 1229 EC (for Rt > RTO)

Using Deep (RLLD), Shallow (RLLS), and R

100

o

x

10

rr

a

_t _i

rr

RLLD / RLLS

This chart provides a method of obtaining Rt from the Dual Laterolog (1229 EC) readings where Rt > Rxo. Rxo

should be determined from an auxiliary survey such as the Micro Laterolog. Rxo, Rlli> an<* RLLS s^ou't' ^ corrected for borehole effects before using this chart. An example illustrating the use of this type of chart is given with Chart 7-68.

7-46 176

WESTERN ATLAS

Rt from 1229 EC (for Rt > Rx0)

Using Groningen (Rllg)> Shallow (Rlls)> and Rxo Current Return at 40 ft

177

Bit

Rt from 1229 EC (for Rt > R^)

raw ATLAS

Using Groningen (Rllg)' Shallow (Rlls)» ant' Current Return at 60 ft

.Invasion Diameter (in.)

100

10

8

rr

o _i

Thick Beds 8-in. Borehole Step Profile

Note: The 1229 EC Shallow is a deeper measurement, which is less then but closer to the depth of investigation of the Groningen Deep. For this reason, for a detailed invasion analysis, use the "Normal Deep & Shallow" tornado chart. 1.4

1.0

1.8

RLLG ! RLLS

This chart provides a method of obtaining Rt from the Dual Laterolog (1229 EC) using Groningen (RllG> readinSs where R. > Rxo. This chart is developed for the Groningen setup that has the current return spaced at 60 ft. Rxo

should be determined from an auxiliary survey such as the Micro Laterolog. Rxo, RllG- and RLLS sh°u'd be corrected for borehole effects before using this chart.

An example illustrating the use of this type of chart is given with Chart 7-68.

7-48 178

WESTERN

Rt from 1507 XB (for Rxo > Rt)

ATLAS

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

(0

Freq = 10kHz Thick Beds 8-in. Borehole Step Profile 1.2

1.6

2.0

R ILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined.

This chart should be used when the transmitter frequency is 10 kHz and Rxo is near 1 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-49 179

Rt from 1507 XB (for Rxo > Rt)

WESTERN

ATLAS

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

jj

180

Rt from 1507 XB (for Rxo > Rt)

Dual-Phase Induction Log (DPIL) • Shallow Focused Log (SFL)

181

WESTERN

ATLAS

rim?"

Rt from 1507 XB (for Rxo > Rt)

Dual-Phase Induction for (DPIL) - Shallow Focused Log (SFL)

Diameter (in.)

50

J60

70

Freq = 10kHz Thick Beds 8-in. Borehole Step Profile

RILM I RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > R,. Rxo should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 10 kHz and Rxo is near 10 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-52 182

WEST! ATLA8

RS11

WESTERN

Rt from 1507 XB (for Rxo > Rt)

ATLAS

Dual-Phase Induction Log for (DPIL) - Shallow Focused Log (SFL)

Freq = 20 kHz Thick Beds 8-in. Borehole Step Profile

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo should be determined by an auxiliary survey such as the Micro Laterlog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined.

This chart should be used when the transmitter frequency is 20 kHz and Rxo is near 10 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-63 183

Rt from 1507 XB (for R^, > Rt)

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

Invasion Diameter (in.)

20

Q

10

cc" CO

rr

Freq = 40 kHz Thick Beds 8-in. Borehole Step Profile

nILM ' nILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from (he chart. The depth of nitrate invasion may also be determined. This chart should be used when the transmitter frequency is 40 kHz and Rxo is near 10 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-54 184

WESTERN ATLAS

Rt from 1507 XB (for Rxo > Rt)

ATLAS

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL) ^

50

Invasion Diameter (in.)

20

10

co

Freq = 1OkHz Thick Beds 8-in. Borehole Step Profile

RILM l RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined.

This chart should be used when the transmitter frequency is 10 kHz and Rxo is near 20 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

(^ 7-55 185

Rt from 1507 XB (for R^ > Rt) Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

Invasionpiarneterfln.)

40 i 50

:60.70

Freq = 20 kHz

Thick Beds 8-in. Borehole Step Profile

RILM l RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo should be determined by an auxiliary survey such as the Micro Laterlog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 20 kHz and Rxo is near 20 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-56 186

WESTERN ATLAS

Rt from 1507 XB (for Rxo > Rt)

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

50

20

10

CO

Freq = 40 kHz Thick Beds

8-in. Borehole

Step Profile

R

/ R

nILM ' nILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo

should be determined by an auxiliary survey such as the Micro Lateroiog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 40 kHz and Rxo is near 20 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-57 187

Rt from 1507 XB (for R^ > Rt)

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

Invasion Diameter (in.)

40 \ 50

R/R ILD

: 60 70

100

Q

CO

DC

10

Freq = 10kHz Thick Beds 8-in. Borehole Step Profile

R ILM

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo

should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 10kHz and Rxo is near 50 ohm-m.

Instructions for using the chart are the same as those used in the Chart 7-67 example.

758 188

WE8TERN ATLAS

Rt from 1507 XB (for Rxo > Rt) Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

100

DC

10

Freq = 20 kHz

Thick Beds 8-in. Borehole

J

Step Profile

RILM/RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rx0 should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 20 kHz and Rxo is near 50 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

/

759 189

WESTERN ATLAS

Rt from 1507 XB (for Rxo > Rt)

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

100

Q

of CO

10

■i Freq = 40 kHz \ Thick Beds

} 8-in. Borehole Step Profile

RILM ' RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rx0 > Rt. Rxo should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 40 kHz and Rxo is near 50 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-60 190

WESTERN

Rt from 1507 XB (for Rxo > Rt)

ATLAS

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL) 0

"a! CO

DC

Freq=1OkHz Thick Beds 8-in. Borehole Step Profile

J\

nILM' nILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo

should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined.

This chart should be used when the transmitter frequency is 10 kHz and Rxo is near 100 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-61 191

Rt from 1507 XB (for Rxo > Rt)

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

Invasion Diameter (in.)

rr"

""of CO

rr

j Freq = 20 kHz Thick Beds : 8-in. Borehole : Step Profile

RILM l RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo should be determined by an auxiliary survey such as the Micro Laterlog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 20 kHz and Rxo is near 100 ohm-m. Instructions for using the chart are the same as those used in the Chan 7-67 example.

7-62 192

Rt from 1507 XB (for Rxo > Rt)

Dual-Phase Induction Log (DPIL) - Shllow Focused Log (SFL)

100

Q

rr~ CO

0C

10

Freq = 40 kHz Thick Beds 8-in. Borehole Step Profile

RILM ! RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo > Rt. Rxo

should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 40 kHz and Rxo is near 100 ohm-m. Instructions for using the chart are the same as those used in the Chart 7-67 example.

7-63 193

Rt from 1507 XB (for Rxo < Rt)

HSit

raw ATLAS

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

\

.01

.1

RILM / RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo < Rt. Rxo

should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of Filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 10 kHz and Rxo is near 1 ohm-m.

Instructions for using the chart are similar to those used in the Chart 7-67 example.

7-64 194

Rt from 1507 XB (for Rxo < Rt)

Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

.01

.1

RILM ' RILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo < Rt. Rxo should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined.

This chart should be used when the transmitter frequency is 20 kHz and Rxo is near 1 ohm-m. Instructions for using the chart are similar to those used in the Chart 7-67 example.

7-65 195

Rt from 1507 XB (for Rxo < Rt) Dual-Phase Induction Log (DPIL) - Shallow Focused Log (SFL)

rr~

.01

.1 R

/ R

nILM ' nILD

This chart provides a method of obtaining Rt from the Dual-Phase Induction Log readings where Rxo < Rt. Rxo

should be determined by an auxiliary survey such as the Micro Laterolog, but an estimate of Rxo can be made from the chart. The depth of filtrate invasion may also be determined. This chart should be used when the transmitter frequency is 40 kHz and Rxo is near 1 ohm-m.

Instructions for using the chart are similar to those used in the Chart 7-67 example.

7-66 196

WESTERN ATLAS

Rt from Dual Induction - Focused Log (Rt < Rxo)

Truck Beds B-in. (203-mm) Borehole

Step Profile No Skin Effect

i

I

i

I

I

1 .

This chart provides a method of obtaining R, from tlic Dual 1 nduction-Focused Log readings where R, is less than Rw The depth of filtrate invasion may also be determined. Charts 6-12 and 6-13 compute logs based on the following equations:

where R_o = resistivity of formation invaded by drilling fluids; R, = resistivity of undisturbed formation; J = geomeiric factor for Focused Log at the invasion diameter; G = geometric factor for Induction Log ai the invasion diameter; FL = Focused Log; ILM = Induction Log Medium; 1LD = Induction Log Deep Example

Given: Rfl/Rild = 10 Q-m/l Q-m = 10; R!Lm/R|ld = 1-4 S-m/1 Q-m = 1.4 Deiermine: dj = 39 in., R^/R, = 18.5; R,/Rild = 0.95; R, » {R,/R[Ld) R]LD = 0.95 fi-m

7-67 197

KSifl

WESTERN

ATLAS

R, from Dual Induction-Focused Log (Rj > 8LJ

15 - d- (mm)

2C

/ 40C

m-i- / "V/V

Thick Beds

■in. (203-mm) Borehole Step Profile No Skin Effect

This chart provides a method of oblaining R, from the Dual Induction-Focused Log readings where R, is greaicr llian

RK0. Rxo should bo determined by an auxiliary survey such as the Micro Laterolog.

Example

Given; R|Ld/rmi = 20 Q ■ m/5 Qtti = 4; Rild^ILM = 20 Q"m/10 Q'm = 2

Determine; d| « 50 in., RS11/R, - 0.17; R,/R[ld = 1.5; Ri - (Rt/R]LD) RlLDJ l-5 x 20 - 30 Q'm 7-68 198

WESTERN ATLAS

Rt from Deep Induction, Focused Log, and Rxo

Rxo'RILD

10 in. (250 mm)

15 in. (400 mm) 20 in. (500 mm) 30 in. (750 mm)

0.1

RIO/RFOC

Thick Beds

8-in. (203-mm) borehole RjlD is skin effect corrected. RFOC is borehole corrected.

7-69 199

WESTERN ATLAS

Rt from Deep Induction, Short Normal, and Rxo

100

M-lnf0*>6-m)H^T;^:ini:(iB0p'imrn)--:

r

i

40 tn.-(1-m) /--j- -~ 16 inr^400 mm)

50

- I -

- ! - - J

\

'

J -

■

','

40

30

20

RXo'R.ld 10

20

This chart is for R^ > R( and R^, < 40. Thick Beds 8-in. (203-mm) borehole

RjlD is skin effect corrected.

7-70 200

30

40

SO

100

KSil

WESTERN

ATLAS

Determination of Water Saturation by Archie's Formula

201

iSia

WESTERN ATLAS

202

iSftfl

WESTERN ATLAS

203

WESTERN

ATLAS

204

iSil

WESTERN ATLAS

Resistivity of Mixed Waters, R7, for Rocky Mountain Method

100

90 80 70

60 50

40

30

10

9 8 7

Fine-grained formation, low permeability

0.10

Average formation

0.075

Coarse-grained formation, high permeability 0.05

-I

i—I—l—L

L 5

6

7

9 10

20

30

40

50

This chart is used to adjust the fluid resistivity values in the invaded zone for the effect of mixing the mud filtrate with the formation waters. Example

Given: Rmf/Rw = 10.0; z = 0.075 Determine: Rz/Rw; Rz/Rw - 5.9 (Refer to next chart for Sw determination)

7-75 205

WESTERN

ATLAS

1

-> 206

Resistivity/Porosity Crossplot (for F = <|r2)

Conductivity, Ca

Resistivity, Ra

(mmho/m)

(Q-m)

100-

10

80-

15

2.72

2.70

2.68

2.66

2.64

2.62

2.60

2.58

2.56 2.54 2.52 2.50 10

1-0 Bulk density, pb (g/cm3 or Mg/m3) Porosity, $ (%)

Note: The saturation scale on die right side of the chart is intended as a sliding scale; i.e., it is moved horizontally until the "100 mark" intersects the line representing 100% S™.

7-77 207

WESTERN ATLAS

Resistivity/Porosity Crossplot (for F =

208

ATLAS

209

WESTERN

ATLAS

Determination of Rwa, Sw and p

Rwa Determination

Sands

(Q-m)

Carbonates

3-

-

3

4- -

A

(Q-m) 50

5-- 5

-

25

-

20

-

15

*— 10

- -

0.02

■ 0.01

Conductivity-Derived Porosity (CDP) CDP

Determination

-*-

(S-rn)

Example

A sandstone has a porosity of 24% and R, = 3.0 Q-m; Rtt = 0.02 Q-m

Water Zones:

Tind:

Oil/Gas Zones:

= 0.225 Q-m

Sw = 30%

Km = R/F

Note; Conductivity-derived porosily is valid CDP -

il/m

only when Rwa = Rw.

7-80 210

WESTERN

ATLAS

Dielectric Water Attenuation vs. Water Resistivity Relationship

2000

1750

1500

1S

1250

a

c

j^\ 750

500

250

0.01

0.1

1

Water Resistivity, Rw (Q ■ m)

V

7-81 211

10

vsai

WESTERN ATLAS

Dielectric Water Propagation Time vs. Water Resistivity Relationship

103

"a

Id

CD

OJ Q. o

102

a

a

o

68° F (20DC] 140°F (60°C) 212°F (100°C)

101 0.01

0.1

1

Water Resistivity, R

7-82 212

(Q-m)

10

WESTERN

ATLAS

Dielectric Response in a Homogeneous Medium (200 MHz)

36

7.2

1O.a

WA

1B0

216

25 2

388

32A

360

= 6.0 in. (152 mm)

= 9.0 in. (229 mm) BO

100

120

1&)

Phase Angle (a)

0

05

36

7.2

108

14.4

1B0

216

2S.S

288

60

eo

too

-120

140

160

360

-

a,

1

<

Phase Angle (°>

7-S3 213

180

Kit

WESTERN

ATLAS

Dielectric Response in a Homogeneous Medium (47 MHz)

Propagation Time, t

g

"5. <

60

ac

IDC

Phase Angle {°;

Frequency-dependent approximate values " Approximate values

where

£0 = 8,854 x 10 ~12 farads/m £

7-84 214

= dielectric constant (farads/m).

fSfel

Water Saturation from Dielectric Propagation Time (Clean Formations)

215

WESTERN

ATLAS

Determination of Ivv

E

7° w*

SO

100

150

200

Equivalent NaCI Concentration, kppm

Ew = 22.1957 + 0.3384C + 1.7587 X

C2 + 0.1340 X IF6 C3

where Ew = Sigma water, capture units (10"3 cm"1). C

= NaCI concentration in kppm.

NaCI equivalent = 1.645 x Cl

8-1 217

250

WESTERN ATLAS

Iw for Boron Compounds in Water

Quantity of Boron Compound, CB (kg/m3) 10

15

20

25

30

4

6

8

10

12

35

u

100

50

14

Quantity of Boron Compound, CB (Ib/bbl)

Equation English

8-2 218

Metric

= 24.8 x CB + 23.0

X

= 8.7 x CB + 23.0

= 20 x C,j + 23.0

Z. = 7.0 x CB + 23.0

= 12.9 x C,j + 23.0

Z. = 4.5 x CB + 23.0

WESTERN ATLAS

Determination of LCH4


A

X

I

10 8

ICH = [Reservoir Pressure (psi)

- B]/M

°C = (°F - 32)/1.8

8-3 219

10

12

14

ESftl

WESTERN ATLAS

220

Correction of Igas for Condensate Content

u

(1.01 X

+ B

8-5 221

WESTERN ATLAS

mi

WESTERN ATLAS

Determination of Xoj| for Varying Gas/Oil Ratios %

^

222

RSIfl

WESTERN

ATLAS

WESTERN

ATLAS

PDK-100 Sigma Borehole and Diffusion Correction

5.5-in. Casing — 8-in. Borehole

-10-

-12

10

20

30

40

50

60

PDK Log SGMA (c.u.)

5.5-in. Casing — 8-in. Borehole

-2

3, <

-4

o CO

o

I

8

-8

-10

-12 10

20

40

30

PDK Log SGMA (c.u.)

8-8 224

50

60

WESTERN

Borehole Salinity Corrections for

ATLAS

Sandstone Formation (7-in. Casing — 8-in. Borehole)

-6

-8 10

Salinity = 75 k

_L 20

30

40

50

60

PDK Log SGMA

Salinity = 250 k

'00* -6

10

20

30

40 PDK Log SGMA

8-9 225

50

60

PDK-100 Diffusion Corrections to SGMA for Sandstone Formation (9V»-in. Casing — 12-in. Borehole)

20 r

15

10

10

PDK log SGMA

20

15

10

8

Borehole Salinity = ?sn u

10

8-10 226

WESTERN ATLAS

WESTERN ATLAS

C/0 Ratio Response to Varying Lithology and Saturations

1.7

1.6

1.5

1.4

1.3 10

20

Porosity, 4> {%)

This chart is normalized to 6%-in., 32-lb/ft, freshwater-filled casing.

8-11 227

30

ES11

WESTERN ATLAS

Inelastic Ca/Si Ratio Response to Varying Lithology and Porosity

1.0

0.90 o

I

0.80

10

15

20

Porosity, 4 (%)

This chart is normalized to 6%-in., 32-lb/ft, freshwater-filled casing.

8-12 228

25

30

35

\

Capture Si/Ca Ratio Response to Varying Lithology and Porosity

1.40

1.30

Energy Intervals SI: 3.17 - 4.65 MeV

Ca: 4.86 - 6.62 MeV

<0

1.20 CO

Limestone (Fresh Water and/or Oil) 1.10

1.00 10

15

20

Porosity, + (%)

This chart is normalized to 6%-in., 32-lb/ft, freshwater-filled casing.

8-13 229

25

30

35

C/O Oil Saturation Correction vs. Cement Thickness

100

90

80

70

7 i

60

50

100

Apparent Oil Saturation, So (%)

This chart is nonnalized to 6%-in., 32-lb/ft, freshwater-filled casing.

8-14 230

WESTERN

ATLAS

C/0 Ratio Correction for Oil Density (Gravity °API)

0.20

0.15

0.10

0.05

15

20

25

30

Porosity, $ (%)

jf

Cased Hole Open Hole

This chart is normalized to 6%-in., 32-lb/ft, freshwater-filled casing.

8-15 231

35

ESlf

WESTERN ATLAS

Capture/Inelastic Ratio and Porosity Correlation

0.45

0.40

o

0.35

I

0

0.30

0.25

0.20

10

20

Porosity, $ (%)

This chart is normalized to 6%-in., 32-lb/ft, freshwater-filled casing.

8-16 232

30

WAM

WESTERN ATLAS

Cement Compressive Strength from Segmented Bond Tool Log 25.0

22.5

20.0

17.5

15.0

o

I CO

io.o

50

2.5

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Casing Thickness (in.)

This chart is intended to provide an estimate of the compressive strength of bonded cement using the attenuation readings from the Segmented Bond Tool (SBT™) log.

Enter the chart on the left with the attenuation in dB/ft, while at the same time entering the casing wall thickness (in.) from the bottom of the chart. The point at which the two lines intersect is the estimated compressive strength (psi) of the bonded cement.

9-1 233

1.1

Kill

WESTERN ATLAS

Cement Compressive Strength from Series 1423 Bond Attenuation Log

Casing O.D. (mm]

273244194178

Cement

140

127

115

5.5

5.0

45

Compressive Strength

psi (MPa)

Standard API Cement

Foam Cement

(30) 4000 — (25)

3000 —

(20) —

(15)--2000 —

(10)

1000 —

— 1000

—

I

—aoo )

(5)

Casing Thickness

(3) (4)

(2)

500

250

(3)

(1) 100 —

(0.5) —

I

— 300

(2)

65

9.625 f

10.75

7.0

7.625

Casing O.D. (in.)

Enter the nomogram along the attenuation scale and project a straight line through the casing thickness to read cement compressive strength. Attenuation can be read directly Irom the Bond Attenuation Log.

9-2 234

I2M1

WESTERN

ATLAS

Cement Comprcssive Strength from Series 1456 Dual Receiver Bond

235

WESTERN

Cement Cnmprcssive Strength from Series 1412,1415, and 1417

ATLAS

Cement Bond Log Instruments

1415, 1417 TR Span 3 ft 1412

(0,9 m)

TR Span 4 ft

Cement

(1.2 m)

Compressive Strength (psi) (MPa) Foam Cement

100-

Standard Cement

50-

40— 30

30-

3000 -t-320°

24

Q.

II

— 15

2000

2000

26

a. jlj

E

--

— 25

20

10-

0)

4000

165

20-

-

— 10

32

u u. II Q O

(mm)

1000 —

36

6 — 800 —

40

- 1000

—

0.21-5 —

Casing Thickness

-IB

5

500 3

4 —

5003 —

52

■

—

2 2S0 1

— 100

300 — — 0.5 2 —

— 50 — 03 200 — 1 —

Casing O.D. (in)

100 —

This chart is intended to provide an estimate ot the campfGsstve strength of bonded cement using the Area! CDL AmpMjda tt is based on fresh water mud-

Enter the nomograph on. the led with the CBL amplitude; then follow the diagonal lines to the casing si^e. Extend from this point horizontally to define attenuation. Connect the attenuation with the appropriaie casing thickness and extend lo the psi to Gsiimaie the compressive strength of the bonded cement,

This chart may also be used to determine attenuation in bonded pipe when the compressive strength of the cement is known. For this purposa, the chart is entered at the right and a line extended through the casing wall thickness to read attenuation. From this point, extend the line

horizontally to the pipe size. Then (allow the diagonal lines to the amplitude to indicate the expected amplitude.

9-4 236

WESTERN ATLAS

Example Form for Information Critical to CBL Interpretation INFORMATION IMPORTANT TO THE INTERPRETATION OF CEMENT BOND LOGS

Operating Company.

Well Name.

Field

County

Location

Sec.

Twp..

Depth Measured from

DF.

GL.

Total Depth.

Casing Fluid Type.

Average Well Drift

Range.

KB.

Date

State.

Fluid Density.

°

From.

Fluid Level.

To.

From.

To.

Centralizer Depths

Scratchier Depths.

Pipe Reciprocated from

DV Tool No. 1 @

hrs to

hrs;

Pipe Rotated from

ft (m), DV Tool No. 2 @

Float Collars No. 1

hrs to

ft (m), DV Tool No. 3 @

No. 2.

No. 3.

Was an open hole caliper run?

Was an open hole acoustic log run?

9-5 237

hrs

ft (m)

WESTERN ATLA8

Example Form for Cement Data Critical to CBL Interpretation

CEMENT DATA IMPORTANT TO THE INTERPRETATION OF CEMENT BOND LOGS

Date(s) of Cement Job(s) Type of Job

D Surface □ Production

D Protection D Liner

Depth Interval from

□ Intermediate D Squeeze ft(m)

ft (m) to.

Type of Cement: Class

Sxs.

Additive Name.

Retarder Name.

Class

Sxs.

Additive Name.

Retarder Name.

Class.

Sxs.

Additive Name.

Retarder Name.

Class.

Sxs.

Additive Name.

Retarder Name.

Slurry Weight.

Sxs.

. yield (ft3 or m'/sx).

Weight.

Sxs.

. yield^orm'/sx).

Bbls Water Used

Volume.

Type Preflush Fluid Breakdown Pressure.

Max. Pressure

Mix No. 3.

Mix No. 2

Mix No. 1

. hrs

@.

Stage 3.

Stage 2.

Stage 1

Pressure Released.

Final Max. Pressure

hrs

Date.

ft(m)

Intended Cement Top. hrs

Cement in place (static)

Cement job evaluation:

Date/Time.

□ Good

Date.

D Some problems noted below

COMMENTS:

9-6 238

D Poor

Kit

Guidelines for Practical Interpretation of Variable

Density Logs and Acoustic Waveform Signature

239

ERN

ATLAS

Guidelines for Practical Interpretation of Variable

WESTERN

ATLAS

Density Logs and Acoustic Waveform Signature

VARIABLE DENSITY 2001200 P-Wave

S-Wave i

Shear _

Waves

Fast Formation

Arrivals

Compressional Waves

1

9-8 240

WESTERN ATLAS

Casing Sizes Threaded, Coupled Type Nonupset

O.D.

8-5/8

9 127.0

5-1/2

6

6-5/8

139.7

152.4

168.3

177.8

7-5/8

8-5/8

193.7

219.1

4.560

115.82

11.50

17.11

0.220

mm

219.1

228.6

5.59

4.494

114.15

13.00

19.34

0.253

6.42

4.408

111.96

15.00

22.32

0.296

7.52

4.300

109.22

17.70

26.34

0.3S0

8.89

4.276

108.61

18.00

26.78

0.362

9.20

4.154

105.51

21.00

31.25

0.423

10.74

5.044

128.12

13.00

19.34

0.228

5.79

5.012

127.31

14.00

20.83

0.244

6.20

4.974

126.34

15.00

22.32

0.263

6.68

4.950

125.73

15.50

23.06

0.275

6.99

4.892

124.26

17.00

26.34

0.304

7.72

4.778

121.36

20.00

29.76

0.361

9.17

4.670

118.62

23.00

34.22

0.415

10.54

5.524

140.31

15.00

22.32

0.238

6.05

5.500

139.70

16.00

23.81

0.250

6.35

5.424

137.77

18.00

26.78

0.288

7.32

5.352

135.94

20.00

29.76

0.324

8.23

5.240

133.10

23.00

34.22

0.380

9.65

6.135

155.83

17.00

26.34

6.049

0.245

6.22

153.65

20.00

29.76

0.288

7.32

9-5/8

244.5

in.

!.D.

mm

Wt. Ib/ft kg/m

Casing

Thickness in. mm

7.775

197.49

38.00

56.54

0.425

10.80

7.725

196.22

40.00

59.52

0.450

11.43

7.651

194.34

43.00

63.98

0.487

12.37

7.625

193.68

44.00

65.47

0.500

12.7

7.511

190.78

49.00

72.91

0.557

14.15

8.290

210.57

34.00

50.59

0.355

9.02

8.196

208.18

38.00

56.54

0.402

10.21

8.150

207.01

40.00

59.52

0.425

10.80

8.032

204.01

45.00

66.96

0.484

12.29

7.812

198.43

55.00

81.84

0.594

15.09

9.063

230.20

29.30

43.60

0.281

7.14

9.001

228.63

32.30

48.06

0.312

7.93

8.921

226.57

36.00

53.57

0.352

8.94

8.835

224.41

40.00

59.52

0.395

10.03

8.755

222.38

43.50

64.73

0.435

11.05

8.681

220.50

47.00

69.94

0.472

11.99

8.535

216.79

53.50

79.61

0.545

13.84

10

254.0

9.384

238.35

33.00

49.10

0.308

7.82

[0-3/4

273.1

10.192

258.88

32.75

48.73

0.279

7.09 8.84

11-3/4

298.1

10.054

255.37

40.00

59.52

0.348

10.050

255.27

40.50

60.26

0.350

8.89

9.960

252.98

45.00

66.96

0.495

10.03

9.950

252.73

45.50

67.70

0.400

10.16

9.902

251.51

48.00

71.42

9.850

250.19

51.00

75.89

0.395 0.450

11.43

10.77

9.782

248.51

54.00

80.35

0.424

12.27

9.760

247.90

55.50

82.58

0.450

12 57

11.150

283.21

38.00

56.54

0.300

7.62

11.084

281.53

42.00

11.000 10.880 10.772

279.40 276.35 273.61

47.00 54.00 60.00

62.50 69.94 80.35

0.333 0.375 0.435

9.53 11.05

89.28

0.489

12.42

59.52

0.308

7.82 7.14

8.46

5.989

152.12

22.00

32.74

0.318

5.921

8.08

150.39

24.00

35.71

0.352

5.855

8.94

148.72

26.00

38.69

0.385

5.761

146.33

9.78

27.00

12

304.8

11.384

289.15

40.00

40.18

0.432

10.97

5.791

147.09

28.00

41.66

0.417

330.2

12.438

315.93

40.00

28.80

42.85

0.394

0.320

8.13

142.62

32.00

47.62

0.505

12.83

74.40

0.359

9.12

6.538

166.07

17.00

26.34

0.231

45.00 50.00 54.00

66.%

5.615

10.01

313.94 311.% 310.39

0.281

148.26

12.360 12.282 12.220

59.52

5.837

10.S9

13

5.87

80.35

0.390

9.91

6.456

163.98

20.00

29.76

0.272

322.96

48.00

71.42

0.330

162.51

22.00

32.74

0.301

7.65

12.615

8.38

6.398

6.91

12.715

320.42

54.50

81.10

0.380

9.65

6.366

161.70

23.00

34.22

0.317

8.05

12.515

317.88

61.00

90.77

0.430

10.92

12.415

315.34

68.00

101.18

0.480

12.19

12.347

315.90

72.00

107.14

0.514

13.06

6.366

160.93

24.00

35.71

0.332

8.43

6.276

159.41

26.00

38.69

0.362

9.20

6.214

157.84

28.00

41.66

0.393

9.98

6.184

157.07

29.00

43.15

0.408

6.154

156.31

30.00

44.64

0.423

13-3/8

339.7

12.175

309.25

83.00

123.50

0.600

15.24

10.36

14

355.6

13.344

338.94

50.00

74.40

0.328

8.33

10.74

16

406.4

15.375

390.53

55.00

81.84

0.313

15.250 15.125

387.35 384.18

65.00 75.00

7.95

96.72

0.375

9.52

111.60

0.438

11.13

15.010

381.25

84.00

124.99

0.495

12.57

23.750 23.650

603.25 600.71

100.00 113.00

148.B0 0.375 168.14 0.425

9.53 10.80

6.094

154.79

32.00

47.62

0.453

11.51

6.004

152.50

35.00

52.08

0.498

12.65

5.920

150.37

38.00

56.54

0.540

13.72

5.836

148.23

40.00

59.52

0.582

14.78

7.125

180.98

20.00

29.76

0.250

6.35

7.025

178.44

24.00

35.71

0.300

7.62

6.969

177.01

26.40

39.28

0.328

8.33

6.875

174.63

29.70

44.19

0.375

9.53

6.765

171.83

33.70

0.430 0.500

10.92 12.70

6.625

178.28

39.00

50.15 58.03

8.097

205.66

24.00

35.71

0.264

6.71

8.017

203.63

28.00

41.66

0.304

7.72

7.921

201.19

32.00

47.62

0.352

8.94

7.825

198.76

36.00

53.57

0.400

10.16

9-9 241

24-1/2

622.3

ATLAS

Pipe Expansion Due to Internal Pressure

Internal Pressure, p, (MPa)

3

4

5

10

20

30

40

50

0.005

s.

0.001

0.0005 0.0004

0.0003

0.005

0.0002

0.004 0.003

0.0001

200

300 400500

1000

3000

Internal Pressure, p, (psi)

Expansion = (10<000174d2 - O.O164d + 0.00464)W + {-0.086d2 + 1.218d - 9.15))/(p0.9fi6) where d = diameter

w = weight/ft p = internal pressure Example

Given: Internal Pressure = 900 psi, 7 in. 23.0 lb/ft

Determine: Expansion

= 0.0034 in.

940 242

5000

10,000

WESTERN

Determining Corrosion in Tubular Goods

243

ATLAS

Magnelog (2934MA) - Wall Thickness Determination

Atlas Wireline Services operates a surface calibration facility at the Western Atlas Center in Houston, Texas. This facility is used to record tool response data for calibration charts that support

Vertilog, Vertiline, and Magnelog. The charts are based on carefully controlled laboratory condi tions, ensuring accurate interpretation of field logs used for pipe evaluation. Magnelog data interpretation involves comparison of the specific frequency versus both phase shift and amplitude. Magnelog charts include:

• A 28-in. spaced log recording in a single string of 7-in., P-l 10, 38 #/ft casing

0.0

0.0

0.1

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Wall Thickness (in.)

0.2

0.3

0.4

Wall Thickness (in.)

9-12 244

0.5

0.6

0.7

"Sltlas Magnelog (2934MA) - Wall Thickness Determination

Atlas Wireline Services operates a surface calibration facility at the Western Atlas Center in Houston, Texas. This facility is used to record tool response data for calibration charts that support

Vertilog, Vertiline, and Magnelog. The charts are based on carefully controlled laboratory condi tions, ensuring accurate interpretation of field logs used for pipe evaluation. Magnelog data interpretation involves comparison of the specific frequency versus both phase shift and amplitude. Magnelog charts include:

• A 28-in. spaced log recording in a dual string of 9.6-in., N-80,40 #/ft casing and 13.3-in., K-55, 68 #/ft casing

1.00 0.90

0.80 0.70

;§.

0.60

| 0.50 | 0-40 0.30 0.20 0.10

0.00 0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1.1

1.2

1.1

1.2

Wall Thickness (in.)

360 320 280

240

I 160 120 80 40

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Wall Thickness (in.)

9-13 245

0.8

0.9

1.0

WESTERN

ATLAS

Reservoir Permeability Estimate from Log Data (Timur Equation)

80

10

20

15

Porosity, + (%)

k - 0.136 v— where tf», Swj are in ^o. Example

Given: Swi = 30%, $ = 25% Determine: k, k = 214 md

10-1 247

25

35

40

KSil

WESTERN ATLAS

Reservoir Permeability Estimate fnmi Log Data (Morris and Biggs Equation)

g

co 01

To

S S

u

i /

k, Permeability (md) for Oil [for Gas. (k](0.1)] 12

16

20

Porosily, t (%)

c = I 250 for oil 79 for gas where ty, Swj are

decimal fractions. Example

Given: Swi = 30%, ty - 25%, oil zone Determine: k, k = 170 ind

lU-2 248

24

28

32

35

HSU

WESTERN ATLAS

Permeability from Resistivity Gradient'' Forpw= 1.025 (Sea Water)

.01

.02

03.04.05.07 0.1

0.2 0.3

0.50.7

Forpw = 1.1 (150,000 ppm Formation Water)

1

2

3

.01

Grad » Basic Resistivity Gradient = f — - —)

.02 .03.04.05.07 0.1

see the paper "Evaluation of Permeability from Electric Log Resistivity Gradients" by \l.P.Tix\cr (Oil & Gas Journal. June 16, VM9)

Solution

RQ = FRW, Ro = 50 x .05 - 2.5 ohm-m. R, at 7050 ft = I5ohm-m.

AR = 35— 15=20ohm-m.

F

= 50.

AD = 7050 — 7010 = 40 ft.

Ru.

=.05atBHT.

Grad. =(20/40) x( 1/2.5) = 0.2

Oil gravity is 30° API.

0.50.7

1

Grad = Basic Resistivity Gradient = (— - — \

Bora discussion of estimation of permeability order of magnitude from logs,

Example

0.2 0.3

Rw is low. use chart For pw -1.1 k is found tobe 85 md,

10-3 249

2

3

WESTERN

Charts and Equations to Estimate Relative Permeability to

ATLAS

Water, Oil, or Gas j

100

10

kra = [(0.9- SW)/(O.9-S1W)]?

10

1

1

20

30

I

40

50

60

70

10

Irreducible Water Saturation, S,w (°/o)

10

20

I

I

I

I

30

40

50

60

70

Irreducible Water Saturation. SiW (%)

20

30

40

50

60

70

80

90

Irreducible Water Saturation, SIW (%)

i\

10-4 250

Chart to Estimate Viscosity of Water

Salinity in ppm NaCI

0.1 0

68

100

150

200

250

Reservoir Temperature, °F

10-5 251

300

350

(At Reservoir Temperature and Saturation Pressure)

Viscosity of Gas-Saturated Oil. cp

o

P

Absolute Viscosity of Gas-Free Crude, cp

I

q

O

Vi

O

en

<

3

C/J

w

©

n

Ril Charts to Estimate Viscosity of Different Natural Gases

Dry Gas

Wet Gas

0.05

Psia

0 02

0.015 -

0

100

200

300

400

0.01

500

0

100

200

300

Temperature. "F

Temperature. *F

Rich Gas

0.02-

0.015 -

0.01

0

100

200

300

Temperature. °F

10-7 253

400

500

400

500

Kifl

WESTERN

Charts to Estimate Water Cut in the IVansition Zone

ATLAS

of an Oil Reservoir 1

70

Very Light Oil (65 60

50 o

1

3

To

to

10

30

10

40

50

60

70

80 10

Water Saturation. S* (%)

20

30

40

50

60

70

80

Water Saturation, S* (%)

Heavy Oil (19° API)

10

20

30

40

SO

60

70

80

Water Saturation.

10

30

40

50

Water Saturation.

10-8 254

70

80

WESTERN

ATLAS

Reservoir Producibility in Shaly Sand

Clay Point

1.0

Fluid Point

10

20

30

40

Effective Porosity, $„ (%)

Shaly reservoir rocks are classified in three categories: producible, non-producible and zones which require stimulation.

This chart is based on field data from the U.S. Gulf Coast area, New Mexico, Colorado and Wyoming. The "q-factor," used to estimate producibility of shaly reservoir rocks is defined as: AC - ({>DEN ^

Q ~

<j>AC

aVsh

^ aVsh

~ <|>DEN + aVsh ~ <j>AC

Tentative permeability cut-offs such as q > 0.4, (q > 2e) have been used. Example

Supposing q = 0.2, 4»e = 20%; point A falls in a producible region.

10-9 255

Formation Strength Parameter Equations in Well Logging Terms

Log-derived values of density, shear travel time and compressional travel time can be mathematically related to Young's Modulus, Bulk Modulus, Shear Modulus and Poisson's Ratio.

DEFINITION OF ELASTIC CONSTANTS Equations in

Elastic Constants

Basic Equations

Interrelation of Equations

9K pv2

Well Logging Terms

3K>i

/ p \ /3At2 - 4At2\

Young's ModuW E = ^-^

E = — - 2,(1 + 0) = 3K(. - 2o)

Bu.k ModuW2'

K - pv2 - 4/3v2

K - j^—^ = , ^-^ = ^^—^

K - P [ -^ ) x ..34 x ,0-

Shear Modulus'"

^ = pv?

j< = "^" = 3K ^^ = -^—

M = A x 1.34 x 1010

Poisson's Ratio'4'

o = 1/2

1

Em

2(1 +o)

9KxE

E

2 + 2o2 + 2o

E = ^ ^T^T ) * ••* * 10" /lAt2 - 4At2\

AtJ

—r

p = bulk density, g/cm3

vc = compressional velocity, ft/s

vs = shear velocity, ft/s

Atc = compressional travel time, /is/ft

Atj = shear travel time, fjsl'ft

1.34 x 1010 = conversion factor

(1) Young's Modulus (E) measures opposition of a substance to extensional stress, E =

F/A

Al/I

(2) Bulk Modulus (K) is the coefficient of incompressibility and measures opposition of substance to

•

,

v

compressional stress, K =

F/A Av/v

(3) Shear Modulus (jO, also called rigidity modulus, measures the opposition of a substance to shear stresses.

Finite values for solids, zero values for fluid, \i =

F/A tan S

(4) Poisson's Ratio (o) is the ratio of relative decrease in diameter to relative elongation, o = Al/1

10-10 256

WESTERN

ATLAS

Interrelationships of Formation Strength Parameters

0.1

0.2 0.3 Poisson's Ratio, a

0.4

0.5

Obtain Values for a (Poisson's Ratio) and u (Shear Modulus) from Previous Charts

3

to

0.1

0.2

0.3

Poisson's Ratio, o

10-11 257

0.4

0.5

IZil

WESTERN ATLAS

Interrelationships of Formation Strength Parameters %

Shear Modulus, u {x 106 psi) 10

5

2.5

2.0

1.5

I 100

150

I/ I

1.0

II 200

Shear Transit Time, Ms (usec/ft)

140

a>

If 100 8 s

I o

0.45 50 40 50

100

150

Shear Transit Time, Ats (usec/ft)

1042 258

200

ESftfl

Determination of Combined Modulus of Strength from Hulk Density and Compression;!I Travel Time

r

r

r

WESTERN ATLAS

WESTERN ATLAS

Log-Derived Clay Content Indicators10"15 LOGGING CURVE

MATHEMATICAL RELATIONSHIP

SPONTANEOUS

Vd = 1.0 - (PSP/SSP) = 1.0 - a

FAVORABLE CONDITIONS

POTENTIAL (SP curve)

Vcl = (PSP - SPmin)/(SSP - SPrain)

UNFAVORABLE CONDITIONS

Water-bearing, laminated shaly

Rmf / rw approaches 1.0. Thin,

sands (
3>Rt ZOnes. Hydrocarbon-bearing.

c < 1.0 as function of clay

Large electro-kinetic and /or invasion effects,

type.

Vd=1.0-cx«

1.0- a=log A/log [(A - Vd x B)/

Knowledge of several parameters required, including a, R,, Rxo, R,,. Similar limitations as for straightforward SP equations.

(l-Vc,xB)] where A = R|/Rxo, B = R,/R,.|

1.0-o = (KxVdxW)/(KxVclxW

K = log-derived coefficient, W = clay porosity from bulk and matrix

+ts»)

Pd; Sx0 = flushed zone water saturation; laboratory-derived, too many requirements.

GAMMA RAY

Vd = (GR -

Only clay minerals are radio

Vd = C(GR -

- GRmin)

Radioactive minerals other than

active.

clays (mica, feldspar, silt).

C<1.0, frequently approx

Only potassium-deficient kaolinite

imately 0.5 when Vd<40lft.

present. Uranium enrichment in permeable, fractured zones.

Vd = (GR-W)/Z

Radiobarite scales on casing.

where W, Z = geologic area coefficient.

Severe washouts (
Vd=0.33(22VCL-1.0)*

Highly consolidated and Mesozoic rocks.

Vd = 0.083(23JVCL-1.0)

Younger, unconsolidated rocks.

Tertiary elastics.

Older, consolidated rocks.

Conditions similar to gamma ray discussion. A = Spectralog

Similar to gamma ray discussion. However, uranium enrichment in

•where VCL = (GR -

SPECTRALOG

fd = (A-Arain)/(Araax-Amin)

Gamma ray spectral logging provides

individual measurements of potassium (K,%) and thorium (Th, ppm) content.

'd = C(A-An,in)/(Anlax-Amin)

readings (K in %, Th in ppm).

Anin = minimum value (K or

rd = 0.33(22VCL-1.0)*

Th) in clean zones.

Vd = O.O83(2"VCL-l.O)» •where VCL = (A-

If several resistivity logs

If Th-curve is used, localized bentonite streaks should be ignored.

Low porosity zones (car-

High porosity water sand, high

bonate, marls), pay zones with low(Sw-Swir).

are available, use the one which exhibits highest resistivity values in sub

where b = 1.0

Rd - values.

, from 0.5 to 1.0. Rd approaches R,

b = 2.0

vd =

tions.

A^ = maximum values (K, Th) in essentially pure shales. - Amin)

RESISTIVITY

ject well.

permeable, fractured zones and radiobarite build-up are no limita

- R«)/ [Rt(Rmax - R«i)] }S

In clean hydrocarbon-bearing zones, one calculates Vd=0.

where (l/b)= 1.0 when

(1/b) =0.5/(1 NEUTRON

High gas saturation or very

low reservoir porosity. +mjn can be varied.

11-1 261

is low.

KSit ATLAS

Log-Derived Clay Content Indicators LOGGING CURVE

MATHEMATICAL RELATIONSHIP

FAVORABLE CONDITIONS

PULSED NEUTRON

Vd = {I-2rain)/ftIlax-2min)

Fresh water environment, low

UNFAVORABLE CONDITIONS

porosity and gas-bearing zones.

Vd =

DENSITY-NEUTRON

Vd =

(PSh - Pf) (+Nma " 1 -0) - (4>Nsh ~ 1 0) (Praa - Pf)

Too low Vd in prolific gas zones. Don't use with severe hole condi

tions. Lithology affected. DENSITY-ACOUSTIC

Vcl =

(Atma-Atf) (P5h-Pf)-(Pma-Pf) (Atsh-Atf) Less dependent on lithology

Badly washed out, wellbores.

and fluid conditions than

DEN-NEU crossplot.

Highly undercompacted forma tions (shallow, overpressures).

Use in gauge boreholes.

NEUTRON-ACOUSTIC Vc,=

(Atma-Atf)(0Nsh- l.O)-(0NmaUse only in gas-bearing zones

Similar effects due to shaliness on

with low S«,.

both logs.

11-1 (Contd) 262

KM

WESTERN ATLAS

Permeability and Water Cut Determination Permeability Determination

This equation assumes viscous or laminar flow of homogeneous fluids through a medium of uniform packing and uniform cross section. In reality, nature does not generally allow a single fluid system. The presence of hydrocarbons presents the problem of having up to three elements (oil, gas, and water) in the

Permeability is a measure of the fluid conductivity of the rocks, i.e., that property which expresses the ease with which fluid moves through the interconnected pores of a rock without alteration of the original rock matrix. The term darcy, after Henry Darcy,16 is used in expressing the unit of measurement of the permeability of a rock. By definition, "a porous medium has a permeability of one darcy when a single phase fluid of one centipoise viscosity that completely fills the voids of the medium will flow through it under 'conditions of viscous flow' at a rate of 1 cm/sec/cm2 of crosssectional area under a pressure or equivalent hydraulic gradient of one atmosphere (76.0 cm of Hg) per centi

pore space. For such cases, the effective permeability, or

the ability of the rock to conduct a particular fluid in the presence of other fluids, is important. The ratio between the effective permeability to a particular fluid at a partial saturation and the permeability at 100% saturation (absolute permeability) is termed relative permeability. Effective permeability and relative permeability are both of primary importance in evaluating a reservoir's poten tial productivity of hydrocarbons and in the determina tion of a reservoir's effective lifetime for economical hydrocarbon production.

meter." Darcy's Law is given by:

M

While Darcy's Law is well stated, assumptions and modifications must be made to the equation to try to determine permeability from well log data. As of this date, no single generalized equation relating wireline log data to permeability can be used under all conditions with accuracy. Table I shows some of the most common approaches to determine permeability from log data. Most of the equations in the table were derived for use in granular sandstone reservoirs; however, these same equations have been used with varying degrees of success in carbonate reservoirs. To achieve any form of accuracy, a large amount of core analysis data are

dx

q

= volume per unit time, cm/sec

k

= permeability constant, darcys

A = cross-sectional area, cm2 M

= fluid viscosity, cP

-j- = hydraulic gradient, atm/cm

necessary to construct a set of calibration curves, before

any empirically based relationship can be accurately applied to any given field. TABLE I

PERMEABILITY ESTIMATION USING WIRELINE LOG DATA Equation kA

Comments dp

k =

Reference

Darcy's Law, single fluid homogeneous porous media

16

f = factor

is

S = inner surface of rock (cmVcm3) A] = empirical constant, sometimes referred to as Kozeny's

19

constant

S

k = A,

= surface area per unit bulk volume

A2 = empirical constant

(1 -

19

So = surface area per unit volume of solid material A3 = empirical constant

Sp = surface area per unit volume of pore space

11-2 263

19

Permeability and Water Cut Determination

264

Bit

WESTERN ' ATLAS

Permeability and Water Cut Determination

265

Logging Parameters for

ATLAS

Various Elements, Minerals, and Rock Types

^

^I

266

Logging Parameters for

Various Elements, Minerals, and Rock Types

267

WES1ERM

ATLAS

Logging Parameters for Various Elements, Minerals, and Rock Types

WESTERN

ATLAS

1

268

Logging Parameters for Various Elements, Minerals, and Rock Types

269

iSil

Logging Parameters for

Various Elements, Minerals, and Rock Types

270

ISM

WESTERN

ATLAS

Logging Parameters for Various Elements, Minerals, and Rock Types

271

Logging Parameters for

Various Elements, Minerals, and Rock Types

272

RSifl

Logging Parameters for

Various Elements, Minerals, and Rock Types

273

Logging Parameters for Various Elements, Minerals, and Rock Types

RSifl

WESTERN ATLAS

i

274

WESTERN ATLAS

Densities of Metamorphic Rocks

275

Classification of Water Saturation Equations in Shaly Clastic Reservoir Rock

276

ATLAS

Classification of Water Saturation Equations in Shaly Clastic Reservoir Rock

C»(1-

Algerefa/.

C, =

Husten and Anton

C, = -jr-Sl

Clay slurry model. F relates to total volume occupied by fluid and clay. Sw relates to fluid-filled pore space.

Q

3

Sw relates to total interconnected pore space.

Laminated sand-shale model. Vih = volume fraction of laminated

■BQvSw*Vsh(

C, =

F=Mo,2 where o, is the total interconnected porosity.

■(-■IE Patchett and Herrick

Comments

Type"

Equation'

Reference

shales only. F relates to total interconnected porosity within shaly-sand streaks. S« relates to total interconnected pore space within shaly-sand streaks.

Poupon and Leveaux

C, = —

"Indonesia" formula.

Poupon and Leveaux

Cf = —

Simplified Indonesia formula for

Raiga-Clemenceau

et al.

q

C, =>—-Si-

4

"Dual-porosity" model: oOlV =o, -o(

'F relates 10 tree-ftunJ porosity unless otherwtse staled. S. relates to tree-fluid pore space unless otherwise stated; equations are written with n • 2 "TYPE EQUATIONS FOR S. RELATIONSHIPS

Type 1:

C, -nS^ + >

Type 3

No interactive term; 5A does not

Type 2:

C,-ftS* *JS'. + > Interactive term. S u does not appear in all terms.

appear in bolt) terms.

,2^

Type 4

No interactive term; S, appears in bolh

C, -aS^-JS^+->S*. interactive term; 6\ appears m all

terms

terms

a ■> predominant sand (arm; ;J - predominani interactive term; i » predominant shale term /. the saturation expononi, is an interactive term. s. the saturation exponent, is a shate term

115 (Contd) 277

KSil

WESTERN ATLAS

References 1.

"Supplement V to 1965 Standard — Letter and

paper presented at the 1979 CWLS Formation

Computer Symbols for Well Logging and Formation Evaluation," JPT (October 1975) 1244-1261.

Evaluation Symposium, Calgary, OctobcrA 14. Larionov, V.V.: "Borehole Radiometry," Nedra, M.

2.

"Supplement V to 1965 Standard — Letter and

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Computer Symbols for Well Logging and Formation Evaluation," JPT (October 1975) 1244-1261.

15. Fertl, W.H.: "Gamma Ray Spectral Data Assists in Complex Formation Evaluation, Trans., 1979 6th

3.

Graton, L.C. and Fraser, H.J.: "Systematic Packing

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Permeability,"/ Geol. (1935) 43, 785-909. 16. Darcy, H.: Les Fontaines Publiques de la Ville de

4.

Folk, R.L.: Petrology of Sedimentary Rocks,

Dijon, Victor Dalmont, Paris (1856).

Hemphill Publishing Co., Austin, TX (1974). 17. Recommended Practices for Determining Perme

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Bigelow, E.L.: "Making More Intelligent Use of

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11-14.

Electric Log Resistivity Gradients," Oil & Gas J. (June 1949).

22. Coatcs, G.R. and Dumanoir, J.L.: "A New

Approach to Improved Log Derived Permeability,

10. Archie, G.E.: 'The Electrical Resistivity Log as an Aid in Determining Some Reservoir Characteristics,"

Trans., 1973 SPWLA 4th Annual Logging Sympo

Trans., AIME (1942) 146, 54-67.

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23. Jones, P.J.: "Production Engineering and Reservoir

11. Fertl, W.H.: "Status of Shaly Sand Evaluation,"

paper I presented at the 1972 4th CWLS Formation

Mechanics (Oil, Condensate, and Natural Gas)," Oil

Evaluation Symposium, Calgary, May 9-10.

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12. Clavier, C. et al.: "The Theoretical and Experimental

Well Logs, Shaybah Field, Saudia Arabia," Trans.,

Basis for the Dual Water Model for the Interpreta tion of Shaly Sands," paper SPE 6859 presented at

1977 SPWLA 18th Annual Logging Symposium,

the 1977 SPE Annual Technical Conference and

June.

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25. Lebreton, F. et al.: "Acoustic Method and Device for Determining Permeability Logs in Boreholes,"

13. Frost, E. and Fertl, W.H.: "Integrated Core and Log

U.S. Patent No. 3,622,969 (1971).

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278

WESTERN ATLAS

References (Contd) 26. Fertl, W.H. and Vercellino, W.C.: "Predict Water Cut from Well Logs," Oil & Gas J. (June 1978). 27. Boatman, E.M.: "An Experimental Investigation of Some Relative Permeability-Relative Electrical Conductivity Relationships," Master's thesis. The University of Texas, Austin, TX (1961). 28. Smithson, Scott B.: Title unknown, Geophys. (August 1971), 4, No. 4, 690-694.

279

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paper presented at the 1979 CWLS Formation

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14. Larionov, V.V.: "Borehole Radiometry," Nedra, M.

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Desai, K. and Moore, E.J.: "Equivalent NaCl

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Ellis, D. et al.: "Mineral Logging Parameters: Nuclear

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Gaymard, R. and Poupon, A.: "Response of Neutron

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280