8. Prod Logging

TRAC III PRODUCTION LOG

PRODUCTION LOGGING SCHOOL

Trac III Production Logs • Background: – Need to obtain production information from wells with rod pumps – Stabilized producing conditions – Convey tools to the production zone, (rod string blocked the production tubing) – Enter the well in the tubing annulus – Very small logging tools due to clearance constraints

• 7/8” diameter production logging tools

Trac III Production Logs • Dynamic, producing (e.g., actual or "real-time") conditions. • Temperature log. • Capacitance log. • Radioactive tracer log. • All logs can be run simultaneously during one trip in the well. • 5 1/2 inch casing and 2 7/8 inch tubing. • 4 1/2 inch casing and 2 3/8 inch tubing.

Trac III Production Logs • • • • • • • •

Positive monitoring of reservoir performance . Detailed, zone-by-zone, information. Changes in the down-hole conditions detected. Reevaluate marginal production wells. Rework watered-out or gassed-out wells. Recompletion of unproductive offset wells. Essential guidance for remedial-workover designs. Cost-effective well recompletions.

Trac III Production Logs • Improved completion techniques for future wells. • Immediate verification of perforation efficiency . • Positive identification of the actual production intervals. • Confirmation of open hole log analysis and assumptions used in the initial completion. • Pinpoint mechanical problems.

Trac III Production Logs    

Document baseline production profile for future reference. Optimize pump placement. Discover unwanted water sources for remedial procedures. Correlate production results with injection profiles for sweep efficiency of floods.  Confirm engineering and geological assumptions and analysis.

Trac III Production Logs  Verify stimulation job effectiveness and techniques.  Plan accurate placement of mechanical isolation tools (bridge plugs and packers.)  Locate thief zones and undesirable cross-flows.  Real-time snap shot of production well.

TRAC III PRODUCTION LOGS TRAC-III Logs: A.

Annulus Logging with 7/8” O.D. Tools.

B.

Flowing Wells

C.

“Y” Tool & Submersible Pump (7/8” Tools).

D.

Memory PLT (Horizontal Applications).

Annulus TRAC-III Production Logging With 7/8” O.D. Tools Tracer Velocities Temperature Logs Collar Locator Gamma Ray

Capacitance Pressure Caliper

Annulus Logging Candidates 4.5” Casing & 2.375” Tubing 5.5” Casing & 2.875” Tubing Or any combination of larger casing and smaller tubing. No liners or other restrictions in the annulus.

ROT: 100 BPD of produced fluids.

7/8” O.D. Tools Rope Socket (15" - 5/8" fishing neck)

Capacitance Tool (40") Caliper (69") Collar Locator (28.5")

Scintillation Gamma Ray Detector (60") Microprocessor Controlled Ejector (75.5") Temperature Tool (37") Memory Pressure Gauge (14”) Total Tool Length with crossovers = 30’

Trac III Production Log - Tools • Collar Locator - 7/8" O. D. by 28" in length. – Magnet coil assembly measures changes in metal thickness.

• Capacitance - 7/8" O. D. by 40" length. – Electrically is a capacitor. – Insulated probe functions as one plate. – Tool housing as the opposite plate. – Various materials passing between the plates have different dielectric properties that change the total capacitance of the circuit.

Capacitance Tool - Parallel Plates

Trac III Production Log - Tools • In most instances, a 3% or more oil cut is necessary before a noticeable change in the capacitance is registered. This 3% threshold varies with the salinity of the water and the gravity of the oil.

Trac III Production Log - Tools • Temperature Tool - 7/8" O. D. by 37" in length. – Accuracy approaching 0.1 degrees Fahrenheit – Linearity and repeatability. – Temperature stability. – Critical for channel detection and other applications.

Trac III Production Log - Tools • Components – Platinum Resistor Temperature Detector (RTD) – Stable crystal oscillator • serves as an accurate, drift-free frequency reference in the tool electronics.

– Individually calibrated in a total immersion oil bath

• Shock and vibration protection – Continuous operation at rated temperature. – Three-day burn-in at maximum rated temperature

Trac III Production Log - Tools • Caliper - 7/8" O. D. by 68" in length. – Three 9. 5" arms – Capable of measuring the I. D. of a hole up to approximately 14" in diameter. – 7/8” O.D. when arms retracted – Surface controlled actuation.

Trac III Production Log - Tools • Ejector - 7/8" O. D. by 74" in length. – – – –

Digitally controlled. Motorized plunger / pressure chamber O-ring sealed exhaust port Consistently eject selected slugs from 0.1 cc to a full 20 cc.

• Detector - 7/8" O. D. by 60" in length. – Scintillation type. – Sodium iodine crystal. – Photo multiplier.

Trac III Production Log - Tools • Signal telemetry – – – – – – –

Pulse encoding Data decoded using DSP technology Data are logged to the hard drive in real time. Simultaneously available for viewing. Logging passes scaled in either axis. Multiple passes merged as required. Merged passes linked with other data.

Trac III Production Log - Preparation  Collar Log & Gamma Ray log for depth correlation  Current Production rates: Water, Oil & Gas  Current well bore sketch and detailed depths of perforations, pump, liner tops, etc.  Recent History of production.  Known effects of remedial work over or water flood.  Well performances vs. Lease performance.

Annulus TRAC-III Preparation •Pull Tubing

•Remove Anchor •Set Pump 100’ above Perfs •Dual Completion Flange •Small Pumping Tee •Slimline Stuffing Box •Remove Bridal Guard •Vertical Clearance Above Annulus Opening

Dual Completion Flange

Top View

Side View

Hand Packoffs

Dual Head Configured & Pump Is Engaged

4.5” Casing & 2.375” Tubing Note that there is not enough room to install a valve on the annulus opening. These flanges are specifically designed for logging in 4.5” casing. A dual completion flange, if there is such, would not allow enough room in the annulus for tool entry.

Production Logging Tidbits

There are no silver bullets in the production logging industry.

Production Logging Tidbits Production logging is an investigative process. It requires the knowledge, experience, and authority to change the logging procedure as needed to define anomalies as they are encountered during the log.

Production Logging Tidbits Avoid the intentional design of tests that rely completely on nuclear based data acquisition. Their maximum radius of investigation is approximately 24 inches from the sensor.

Production Logging Tidbits In production logging, temperature logs are the center of your universe. They are always correct, although sometimes hard to interpret by themselves. Use data acquired from others sensors to help you interpret the temperature logs.

!We Want You On Location! • Production logging is an investigative process • Your knowledge of the lease can make the difference between a good survey and a great survey

Correlation Logs Logs used to align logging depths to previously run open hole and cased hole logs. Avoid the LAST LOG SYNDROME. It is generally acceptable for most production logs to be within 2 to 3 feet of measured depth. However, if you are on the 4th or 5th generation of logs, you may be correlating 10’ to 15’ off depth. Always try to use the original open hole logs or the logs used to perforate the well.

Temperature Logs Producing temperature logs tend to reflect in wellbore and near wellbore events.

Shut-in temperature logs indicate events outside the wellbore. You must know the status of the interior of the wellbore before you can interpret shut-in temperatures.

Capacitance •Fluid Identification •Calibrate between water and gas. •Capacitance VS. Density Tool

Tracer Velocities Modified Velocity Profile Measurement Production fluctuations do not affect the calculations as severely as stationary velocity shots. Same velocity method is used in flowing wells.

Tracer Velocities

Velocity Profile • Pi x r2 x h = Volume of a cylinder • Pro’s: – High resolution of data points – Limited by the spacing from ejector to detector

• Con’s: – Minor plant fluctuations effect calculated rates – I.D. changes have a drastic effect on the calculated rates

Calculations and Interpretations: Volumetric Flow Rates

• Volume = PI x Dia^2 / 4 * L

• Volumetric Flow = Vol / Time

Diameter

Caliper Log

Log Interpretation Intensity Profile

Velocity Profile

Temperature Logs No Flow Shot

Channel Check

Crossflow Check http://www.cardinalsurveys.com

Merged Log

TRAC-III Below Submersible Pump Y-Tool Assembly •Well must have 7” casing to accommodate Y-tool. •Shut-in well & allow fluid to fall below pump •Fish out plug

TRAC-III Below Submersible Pump Y-Tool Assembly •Install running plug on wireline •Lower TRAC-III Tools & Running Plug to “Y” •Lower TRAC-III Tools below pump •Engage pump to seat running plug •Run logs when well is stable

Y-Tool Accessories For Logging Running Plug

Baby Red

Prevents fluids from being circulated by pump.

Used to retrieve plug from Y-tool.

Memory PLT •Horizontal wells are the primary application in the Permian Basin. •No real time feedback allowing procedure modification to maximize information.

•Most wellbore events in producers are not continuous. Your economics must reflect the possibility of multiple runs to accomplish some test objectives. •Most companies that have access to memory tools do not consider production logging a core business. •Great weapon, for the right battle!

TRAC III PRODUCTION LOG

PRODUCTION LOGGING SCHOOL

CARDINAL SURVEYS COMPANY

Eliminate the Guesswork!

TRAC III PRODUCTION LOG

The End