Modern Pressure Transient Analysis of Petroleum Reservoirs: A Practical View

Preface
Overview of Chapters
Contents
About the Author
1 Introduction to Recognized Flow System During Well Testing
	1.1 Fluid Flow in Porous Media
	1.2 Types of Flow Behaviour
		1.2.1 Transient Flow
	1.3 Steady-State Flow
		1.3.1 Pseudo-steady State Flow
		1.3.2 Boundary-Dominated Flow
	1.4 Development of the Diffusivity Equation
	1.5 Infinite-Acting Radial Flow
	1.6 Concepts of Superposition
		1.6.1 Superposition in Time Versus Superposition in Space
		1.6.2 Superposing Pressures Versus Superposing Rates
		1.6.3 Example 1.1
		1.6.4 Example 1.2
	1.7 Radius of Investigation
		1.7.1 Example 1.3
		1.7.2 Example 1.4
		1.7.3 Example 1.5
	1.8 Altered Zone and Skin Factor
	1.9 Modeling Skin of Altered Permeability Area
		1.9.1 Example 1.6
		1.9.2 Example 1.7
	1.10 Wellbore Storage (WBS)
	1.11 Fluid-Filled Wellbore (WBS)
	1.12 Falling Liquid Level in the Wellbore
		1.12.1 Example 1.8
	1.13 Summary
	References
2 Well Test Concepts
	2.1 Flow Regimes and the Diagnostic Plot
	2.2 Power-Law Function
	2.3 Log–Log Derivative of a Power-Law Function
	2.4 Flow-Regime—Specific Diagnostic Plots
	2.5 Flow-Regime-Specific Straight-Line Analysis Plots
	2.6 Flow Regimes
		2.6.1 Radial Flow
		2.6.2 Vertical Well, Infinite-Acting Redial Flow
		2.6.3 Vertical Well Near Single No-Flow Boundary, Hemiradial Flow
		2.6.4 Vertical Well Between Intersecting Sealing Faults
		2.6.5 Radial Composite Reservoir, Radial Flow in Outer Zone
		2.6.6 Hydraulically Fractured Well, Pseudo-radial Flow (PRF)
		2.6.7 Horizontal Well, Early Radial Flow
		2.6.8 Horizontal Well, Early Hemi-Radial Flow (EHRF)
		2.6.9 Horizontal Well, Late Pseudo-radial Flow (LPRF)
	2.7 Linear Flow
		2.7.1 Linear Flow Caused by Hydraulically Created Fracture
		2.7.2 Channel Reservoir, Both Ends Open
		2.7.3 Channel Reservoir, One End Open
		2.7.4 High-Conductivity Hydraulic Fracture, Formation Linear Flow
		2.7.5 Well Near a High-Conductivity Fault
		2.7.6 Horizontal Well, Early Linear Flow
		2.7.7 Example 2.1: (Combined Analyzing of Radial and Linear Flow)
	2.8 Volumetric Behaviour
	2.9 Phenomenon of Wellbore Storage
	2.10 Closed Reservoir, Pseudo-steady State Flow (PSSF)
	2.11 Radial Composite Reservoir With Low Mobility Outer Zone
		2.11.1 Example 2.2
		2.11.2 Example 2.3
	2.12 Spherical Flow Regime
		2.12.1 Limited-Entry Completion
		2.12.2 Partial Penetration
		2.12.3 Example 2.4
	2.13 Bilinear Flow Regime
		2.13.1 Finite-Conductivity Hydraulic Fracture
		2.13.2 Well Near a Finite-Conductivity Fracture
	2.14 Other Flow Regimes
	2.15 Summary
	References
3 Well Test Interpretation Workflow
	3.1 Introduction
	3.2 Well Testing Workflow Steps
		3.2.1 Gather Well Test Data
		3.2.2 Analysis and Quality Control Data
		3.2.3 Deconvolve Data
	3.3 Indicate Flow Regimes
	3.4 Select Reservoir Model
	3.5 Estimate Model Parameters
	3.6 Simulate or History-Match Pressure Response
		3.6.1 Simulation
		3.6.2 Manual History Matching
	3.7 Validate Results
	3.8 Summary
	References
4 Well Test Design Workflow
	4.1 Introduction
	4.2 Define Test Objectives
	4.3 Fundamental Well Test Design Scenarios
	4.4 Alternative Well Testing
	4.5 Collect Data
	4.6 Estimate Reservoir Properties
	4.7 Permeability Estimates
		4.7.1 Example 4.1
	4.8 Estimate Test Period to Reach Expected Flow Regime
		4.8.1 Time to Beginning of Middle Time Region
		4.8.2 Time to Reach Particular Boundaries or Flow Regimes (Infinite-Acting Reservoir)
	4.9 Estimation Test Period Based on Economical Evaluation
		4.9.1 Estimation of the Minimum Commercial Productivity Index
		4.9.2 Estimation of the Minimum Commercial Oil in Place
		4.9.3 Test Period for Minimum Economics
		4.9.4 Estimation of the Minimum Economical Test Time Graphically
	4.10 Estimate Test Rate and Determine Flow Rate Sequence
	4.11 Example 4.2
	4.12 Summary
	References
5 Types of Well Tests
	5.1 Overview
	5.2 Pressure Drawdown Test
		5.2.1 Constant-Rate Production
		5.2.2 Smoothly Changing Rate
	5.3 Type Curve Analysis
		5.3.1 Type-Curve Procedures Using Gringarten Type Curves
		5.3.2 Example 5.4
	5.4 Pressure Buildup Test
		5.4.1 Horner Plot Method
		5.4.2 MDH Plot Method
	5.5 Multiple Well Testing
		5.5.1 Interference Test
		5.5.2 Pulse Tests 
	5.6 Closed-Chamber Test 
		5.6.1 Application of Closed Chamber Testing
	5.7 Summary
	References
6 The Principle of Superposition
	6.1 Overview
	6.2 Principle of Superposition and Constraints
	6.3 Multiple-Well Cases
		6.3.1 Example 6.1
	6.4 Effects of Fluctuating Flow Rates
		6.4.1 Example 6.2
	6.5 Reservoir Boundary Effects
		6.5.1 Example 6.3
	6.6 Effects of Pressure Changes
	6.7 Summary
	References
7 Well Testing Models
	7.1 Reservoir Behaviour
	7.2 Dual Porosity Reservoir
		7.2.1 Dual Porosity Pseudo-steady State Interporosity Flow
		7.2.2 Dual Porosity (Transient Interporosity Flow)
		7.2.3 Example 7.1
	7.3 Dual Permeability Reservoir
	7.4 Summary
	References
8 Gas Well Testing
	8.1 Gas Flow Behaviour
	8.2 Diffusitivity Equation for Gas Flow
		8.2.1 Pseudopressure Function
		8.2.2 Pseudotime Function
	8.3 Gas Well Testing Techniques
	8.4 Flow After Flow Test
		8.4.1 Rawlins-Schellhardt Analysis Method
		8.4.2 Example 8.2
	8.5 Isochronal Test
		8.5.1 Rawlins and Schellhardt's Analysis
		8.5.2 Houpeurt Analysis
		8.5.3 Example 8.3
	8.6 Modified Isochronal Test
		8.6.1 Example 8.4
	8.7 Summary
	References
9 Practical Aspects of Well Test Interpretation
	9.1 Factors Affecting Well Test Interpretation
		9.1.1 Well Test Data Preparation and Verification
	9.2 Impact of Well and Reservoir Conditions on Pressure Responses
		9.2.1 Erratic Wellbore Storage
		9.2.2 Liquid Level at the Wellbore
		9.2.3 Interference Effects
	9.3 Effects of Static Parameters
	9.4 Well Test Deconvolution
	9.5 The Golden Rules of Accurate Test Interpretation
	9.6 Summary
	References