2 - Completion Design

Design Criteria

Internal Use Only

• Well Completion Defined as “the design, selection and installation of equipment and the specification of treatment and procedures necessary to bring the well into production and thereafter to produce in a manner which satisfies the company objectives for the field development” • Conventional Completion Defined as “completions which have both large (min 4 1 /2”) casing and one or more smaller tubing strings”

Internal Use Only

Data Inputs to Formulating Design Criteria Reservoir Parameters

Rock Characteristics

Design Criteria

Fluid Characteristics

Well and Completion Appraisal

Production Constraints

Internal Use Only

Design Criteria Reservoir Parameters Geological Structure

Structural Trap Stratigraphic Trap Unconformities Combinations Salt Domes

Continuity

Permeability Barriers Permeability Contrasts Isotropy

Internal Use Only

Drive Mechanism

Physical Characteristics

Water Drive Gas Cap Solution Gas Combination

Size Shape Thickness Pressure Temperature Water Depth

Geological Structure Fault or Structural Trap

Unconformity or StratigraphicTrap

Impervious Shale

Impervious Shale

Gas

Oil Oil Water

Internal Use Only

Water

Geological Structure Salt Dome

Anticline

Cap Rock Oil Oil

Water

Water

Salt

Internal Use Only

Rock Characteristics Lithological Description

Physical Properties

Chemical Composition

Porosity Clastic Chemical Precipitate Biochemical Precipitate

Permeability Consolidation Pore Size distribution

Composition Contamination Clay Content

Fluid Saturation's

Cementaceous Material

Grain Size & Shape

Scale Forming Materials

Wetability Moveable Fines

Internal Use Only

Fluid Characteristics Physical Properties

Chemical Properties

Composition

Oil Density

Wax Content

Gas Gravity

Corrosive Agents

Viscosity

Asphaltenes

Pour Point

Toxic Materials

G.O.R.

Scale

W.O.R. Surface Tension

Internal Use Only

Production Constraints

Technical Factors

Legislative Considerations

Productivity

Safety Standards

Separator Capacity & Pressure Rating

Disposal of Gas & Water

Export capacity Workover Considerations Operational Flexibility

Political System Taxation Investment Incentives Market Requirements Company Objectives Cash Flow

Preferred Payback period Ultimate Recovery Production profile

Internal Use Only

Environmental

Ease of Access Weather Conditions Built-up Areas Local Industries

Production Zone Preparation

Drilling Activities

Hole Size Deviation Programme Formation Damage (Drilling fluids)

Evaluation Activities

Completion Activities

Coring

Casing Schemes

Testing

Primary Cementation

Logging Fluid Sampling

Design Criteria

Internal Use Only

Mechanical Completion Completion Programme

Installation Procedure

Completion Fluid Perforating Programme

Equipment Design & Selection

Ancillary String Components

Essential Production Equipment

Space Out

Wellhead S.S.S.V Packer

Improving Performance

Operational Flexibility

Flow Couplings

Nipples

Tubing Seals

Circulating Devices

Blast joints

Internal Use Only

S.P.M.

Production Initiation Phase Matrix Extent

Acidization Fracturing Surfactant

Wellbore

Type of treatment

Restore Permeability

Stimulation

Function Increase Permeability

Production Initiation Inducing Flow Clean Up Programme Displace Fluid Cushion

Gas lift

Nitrogen Injection With Coil Tubing Initial Rate & Subsequent Rate of increase

Internal Use Only

Well Test Evaluation

Integration of Well Completion Phase

1 Establish Design Criteria. Update Design Criteria

2 Preparation of Production Zone. 3 Design and Installation of Completion String. 4 Production Initiation & Remedial Measures. 5 Monitoring Well & Completion Performance.

Internal Use Only

Well Workover

• Properties of Drilling Muds - Viscosity - Specific Gravity - Filtrate • Functions of Mud • SKIN – damage to formation in contact with mud

Internal Use Only

Functions of Casing 1) Support the bore hole and prevent caving 2) Isolate shallow unconsolidated zones 3) Provide support for wellhead and BOP equipment and subsequent casing strings 4) Provide sufficient fracture gradient to allow drilling of next hole section

Internal Use Only

Conductor Pipe Surface Casing

Intermediate Casing Production Casing

Production Liner

Internal Use Only

Casing Depths D e p t h

Depth 1

P1

F1

1

Fracture Pressure

Depth 2

P2

F2

2

Pore Pressure Depth 3

P3

Pressure

Internal Use Only

3

•

Purpose of Cementing

1) 2) 3) 4)

Strengthens and supports the casing Protects against corrosion Prevents fluid migration Seals around casing shoe to allow control of formation pressures while drilling ahead

Internal Use Only

Internal Use Only

Liners

12 Reasons for running a liner shown on Page 27 Know 3-4 of these

Internal Use Only

Internal Use Only