Advances in well test analysis during the 1980's and 90'shave been associated with: (a) the use of pressure derivative plots, (b) the common availability of computer software for rapid graphical presentation, (c) the use of non-linear regression (automated type cure matching), (d) the availability of higher precision, high frequency data, both for pressure and flow rate, and (e) the development of new interpretation models, such as for horizontal wells, layered reservoirs and multiphase flow.
This book takes the form of a tutorial emphasizing these aspects of well test interpretation in this new computerized environment. During the book, emphasis is on problem solving, using computerized tools. A companion CD-ROM contains full listings of the data used in many of the examples, as well as a hypertext searchable version of the entire book (in the form of a Windows™ Multimedia Viewer title). A complete well test interpretation software package on the CD-ROM allows you to work with the example data yourself to learn more about how well test interpretation is achieved in practice.
Author(s): Roland N. Horne
Edition: 2
Publisher: Petroway Inc.
Year: 1995
Language: English
Commentary: 600 scanned bitonal original processed with ScanTailor.
Pages: 264
City: Palo Alto
Tags: well test, PTA
Modern Well Test Analysis
COPYRIGHT
Acknowledgements
Contents
1. WELL TEST OBJECTIVES
1.1 Introduction
1.2 Reservoir Evaluation
1.3 Reservoir Management
1.4 Reservoir Description
1.5 Decline Curve Analysis
1.6 Types of Tests
1.6.1 Drawdown Test
1.6.2 Buildup Test
1.6.3 Injection Test
1.6.4 Falloff Test
1.6.5 Interference Test
1.6.6 Drill Stem Test (DST)
1.7 References
2. WELL TEST CONCEPTS
2.1 Basics of Reservoir Models
2.2 Dimensionless Variables
2.3 The Skin Effect
2.3.1 Flow Efficiency
2.3.2 Partial Penetration Skin
2.4 Wellbore Storage
2.5 Infinite Acting Radial Flow
2.6 Semilog Analysis
2.6.1 Semilog Analysis - Illustrative Example
2. 7 Log-Log Type Curves
2.7.1 Type Curve Analysis - Illustrative Example
2.8 Reservoir Boundary Response
2.8.1 Closed Boundaries
2.8.2 Fault Boundaries
2.8.3 Constant Pressure Boundaries
2.9 Radius of Investigation
2.10 Fractured Wells
2.10.1 Finite Conductivity Fractures
2.10.2 Infinite Conductivity Fractures
2.10.3 Uniform Flux Fracture
2.11 Dual Porosity Behavior
2.12 Summary of Responses in Time Sequence
2.13 Superposition
2.14 Time Superposition - Multirate Tests
2.15 Buildup Tests
2.15.1 Buildup Tests - Illustrative Example
2.15.2 Treating Buildups as Drawdowns
2.15.3 Average Reservoir Pressure
2.16 References
3. COMPUTER-AIDED ANALYSIS
3.1 Overview
3.2 Graphical Presentations
3.3 The Derivative Plot
3.3.1 Derivative Plots for Buildup Tests
3.3.2 Calculating Derivatives
3.3.3 Estimating Dual Porosity Parameters on Derivative Plots
3.4 Diagnostic Plot Evaluation
3.5 Data Preparation
3.5.1 Number and Frequency of Data
3.5.2 Datum Shifting
3.6 Nonlinear Regression
3.6.1 Confidence Intervals
3.6.2 Initial Pressure
3.6.3 Multirate and Variable Rate Tests
3. 7 Desuperposition
3.8 Interpretation Sequence
3.9 Non-ldeality
3.10 References
4. GAS WELL TESTS
4.1 Introduction
4.2 Real Gas Pseudopressure and Pseudotime
4.3 Calculating Pseudopressures
4.4 Using Normalized Pseudopressure for Analysis
4.5 Using Pseudopressure for Analysis
4.6 Rate Dependent Skin Effect
4.7 References
5. MULTIPHASE WELL TESTS
5.1 Introduction
5.2 Perrine's Approach
5.3 Pressure Squared Approach
5.4 References
6. DESIGNING WELL TESTS
6.1 Introduction
6.2 Variable Dependency
6.3 Test Duration
6.4 Flow Rate Considerations
7. ADVANCED TOPICS
7.1 Horizontal Wells
7.1.1 Flow Regimes
7.1.2 Estimating Parameters
7.1.3 Nonlinear Regression
7.2 Multilayered Well Analysis
7.2.1 Tests without Flow Measurements
7.2.2 Tests with Flow Rate Measurement
7.3 References
8. WORKED EXAMPLES
8.1 Drawdown Test Example
8.1.1 Identifying Flow Periods
8.1.2 Estimating Parameters
8.1.3 Type Curve Match
8.1.4 Comparison of Graphical Estimates
8.1.5 Time Shift Errors
8.1.6 Pressure Shift Errors
8.1.7 Confidence Intervals
8.1.8 Nonlinear Regression
8.1.9 Radius of Investigation
8.1.10 Truncated Data
8.1.11 Simultaneous Rate-Pressure Data
8.2 Bounded Reservoir Example
8.2.1 Ambiguity
8.3 Buildup Test Example
8.3.1 Test Without Boundary Effects
8.3.2 Effects of Boundaries
8.3.3 Knowledge of pwf
8.4 Fractured Well Examples
8.4.1 Finite Conductivity Fracture Example
8.4.2 Infinite Conductivity Fracture Example
8.5 Dual Porosity Examples
8.5.1 Example with Modest Wellbore Storage
8.5.2 Example with Larger Wellbore Storage
8.5.3 Buildup Effects
8.6 Interference Test Examples
8.6.1 Single Flow Rate Example
8.6.2 Multirate Example
8.7 Gas Well Test Example
8.8 References
9. CALCULATING PROPERTIES
9.1 Introduction
9.2 Oil Properties
9.3 Gas Properties
9.4 Water Properties
9.5 Rock Properties
9.6 Total Properties
9.7 References
10. FIELD EXAMPLES
Test 1: Stimulated Well
Test 2: ChannelSand
Test 3: Closed Drainage Area
Test 4: Wedge Shaped Boundary
Test 5: Transition Data
Test 6: Horizontal Well
Test 7: Test from Mechanical Gauge
Test 8: Damaged Well
Test 9: Thermal Recovery Well
Test 10: Uninterpretable Test
Test 11 : Horizontal Well
Test 12: Short Test
Test 13: Short Test
Test 14: Short Test
Test 15: Hydraulically Fractured Well
Test 16: Falloff Test with Prior Shut-In
Test 17: Gas Well Buildup
Test 18: Acidized Well
Test 19: Ambiguous Response
Test 20: Horizontal Well
Test 21 : Downhole Flow Rate Measurement
Test 22: Damaged Well Buildup
Test 23: Hydraulically Fractured Well
Test 24: Dual Porosity Response
Test 25: Geothermal Well
References
Index
