PETE-358: WELL PERFORMANCE

COURSE OUTLINE

1. Introduction

Well Test Objectives

Well Test Types

Inflow Performance Relationship

2. Fundamental Concepts in Well Testing

Flow Regimes: Steady, Pseudo-Steady and

Transient

Skin Effects

Wellbore Storage

Radius of Investigation

Principle of Superposition

3. Analysis of Pressure Drawdown Tests

Infinite-Acting Radial Flow Analysis

Constant Rate Drawdown

Variable Rate Drawdown

Estimating Reservoir Volume

4. Analysis of Pressure Buildup Tests

Analysis and Interpretation

Average Reservoir pressure

Detection of Fault Boundaries

PETE-358: WELL PERFORMANCE

COURSE OUTLINE

5. Computer-Aided Analysis and Interpretation

Pressure Derivative Plot – Diagnostics

Flow Regime Identification

Well, Reservoir and Boundary Models

Pressure Derivative Analysis

Automatic Parameter Estimation

6. Gas Well Testing

Pseudopressure and Pseudotime

Non-Darcy Flow/Rate Dependent Skin

Gas Well Deliverability

Gas Rate Forecasting

7. Well Test Design

Design Considerations

Design Equations

8. Introduction to Horizontal Well Test Analysis

Flow Regime Identification

Analysis of Test Data

Well Performance

• Also known as: Well Testing

Pressure Transient Testing

Reservoir Testing

• Well testing generally refers to generating and measuring pressure variations with time in wells, and using this information to estimate rock, fluid and well properties

• Powerful reservoir description tool. Essential for analysis and improvement of reservoir performance

Classification

• Productivity well testing

• Descriptive well testing

Types of Tests

• Drawdown

• Buildup

• Injectivity

• Falloff

• Interference

• Deliverability

Productivity Testing

Inflow Performance

• Inflow from Reservoir to Well

• Performance depends on

reservoir and fluid properties:

– Reservoir pressure

– Permeability

– Viscosity

– Bottom hole pressure

• The well can deliver only what

the reservoir provides

Inflow Performance

• Inflow performance is usually

expressed in terms of flow rate

versus drawdown pressure or rate

versus bottom-hole pressure

• For single-phase liquids, flow rate

is proportional to drawdown

pressure.

• For gases and gas-liquid systems,

flow rate is not necessarily

proportional to drawdown

Inflow Performance

Inflow Performance

(Liquid)

• q = PI (Pres – Pw)

• PI is the Productivity Index,

which depends on

– Reservoir permeability

– Net thickness

– Drainage area

– Fluid properties

– Well damage or stimulation

A = Oil well: Low productivity

B = Oil well: High productivity

C = Gas well: general