Dynamic Well Testing in Petroleum Exploration and Development

Chapter 1 Introduction1.1 THE PURPOSE OF THIS BOOK1.1.1 Well Test: A Kind of System Engineering1.1.2 Well Test: Multilateral Cooperation1.1.3 Writing Approaches of this Book1.2 ROLE OF WELL TEST IN GAS FIELD EXPLORATION AND DEVELOPMENT1.2.1 Role of Well Test in Exploration1.2.1.1 Drill Stem Test (DST) of Exploration Wells1.2.1.2 Exploration Well Completing Test1.2.1.3 Reserves evaluation1.2.2 Role of Well Test in Predevelopment1.2.2.1 Deliverability Test of Development Appraisal Wells1.2.2.2 Transient Well Test of Development Appraisal Wells1.2.2.3 Well Test of Production Test Wells1.2.2.4 Selection and Evaluation of Stimulation Treatment1.2.2.5 Verifying Reserves and Making the Development Plan1.2.3 Role of Well Test in Development1.3 KEYS OF WELL TEST ANALYSIS1.3.1 Direct Problem and Inverse Problem in Well Test Research1.3.2 How to Understand Direct Problems1.3.2.1 Analyzing the Formation Where the Oil/Gas Well Locates and Classifying it Geologically1.3.2.2 Classifying, Simulating, and Reproducing Formation from the Viewpoint of Flow Mechanics1.3.2.3 Constructing the Well Test Interpretation Model and Resolving the Related Problem1.3.2.4 Expression Forms of Research Results of Resolving Direct Problems in Well Test1.3.3 Describing Gas Reservoirs: Resolving Inverse Problem1.3.3.1 Well test design1.3.3.2 Acquiring Pressure and Flow Rate Data Onsite1.3.3.3 Graphical Analysis in Well Test Interpretation1.3.3.4 Well Test Interpretation Combining Actual Formation Conditions1.3.3.5 Recommend Knowledge Obtained from Well Test Interpretation to be Applied in Gas Field Development 1.3.4 Computer-Aided Well Test Analysis 1.4 CHARACTERISTICS OF MODERN WELL TEST TECHNOLOGY 1.4.1 One of the Three Key Technologies of Reservoir Characterizations 1.4.1.1 The Distinct Information Here Includes the Following 1.4.1.2 Deficiencies of Well Test Technology 1.4.2 1.4.2 Methods of Gas Reservoir Dynamic Description 25 1.4.2.1 Dynamic Reservoir Description with Deliverability of Gas Wells at the Core 1.4.2.2 New Thoughts in Gas Reservoir Dynamic Description Chapter 2 Introduction 2.1 BASIC CONCEPTS 2.1.1 Steady Well Test and Transient well Test 2.1.1.1 Steady Well Test 2.1.1.2 Transient Well Test 2.1.2 Well Test Interpretation Models and Well Test Interpretation Type Curves 2.1.3 Dimensionless Quantities and Pressure Derivative Curve in Well Test Interpretation Type Curves 2.1.4 Wellbore Storage Effect and its Characteristics on Type Curves 2.1.4.1 Implications of Wellbore Storage Effect 2.1.4.2 Order of Magnitude of Wellbore Storage Coefficient 2.1.4.3 Characteristics of Wellbore Storage Effect on Well Test Interpretation Type Curves 2.1.5 Several Typical Flow Patterns of Natural Gas and their Characteristics on Interpretation Type Curves 2.1.5.1 Radial Flow 2.1.5.2 Steady Flow 2.1.5.3 Pseudo-Steady Flow 2.1.5.4 Spherical Flow and Hemispherical Flow 2.1.5.5 Linear Flow 2.1.5.6 Pseudo-radial Flow 2.1.5.7 Flow Condition in Formation Having been Improved or Damaged 2.1.6 Skin Effect, Skin Factor and Equivalent Borehole Radius 2.1.7 Radius of Influence 2.1.8 Laminar Flow and Turbulent Flow 2.2 Gas flow equations 2.2.1 Definition of Reservoir as a Continuous Medium 2.2.2 Flow Equations 2.2.2.1 Deriving Flow Equations Based on Three Basic Equations 2.2.2.2 Average Flowing Velocity and Flow Velocity of Unit Cell 2.2.2.3 Darcy’s Law Applied for Flow of Viscous Fluid 2.2.2.4 Continuity Equation 2.2.2.5 State Equation of Gas 2.2.2.6 Subsurface Flow Equations of Natural Gas 2.2.2.7 Dimensionless Expressions of Gas Flow Equations 2.2.2.8 Boundary Conditions and Initial Conditions for Solving Gas Flow Equations 2.3 Summary Chapter 3 Gas Well Deliverability Test and Field Examples 3.1 GAS WELL DELIVERABILITY AND ABSOLUTE OPEN FLOW POTENTIAL (AOFP) 3.1.1 Meanings of Gas Well Deliverability 3.1.2 Gas Well Deliverability Indices 3.1.2.1 Deliverability of a Gas Well 3.1.2.2 Absolute Open Flow Potential of Gas Wells 3.1.2.3 Validity of AOFP 3.1.2.4 Initial and Dynamic AOFP 3.1.3 Initial Deliverability, Extended Deliverability, and Allocated Production of Gas Well 3.1.3.1 Initial Deliverability Index 3.1.3.2 Extended Deliverability Index 3.1.3.3 Allocating Flow Rate Index 3.2 THREE CLASSICAL DELIVERABILITY TEST METHODS 3.2.1 Back-Pressure Test Method 3.2.2 Isochronal Test Method 3.2.3 Modified Isochronal Test Method 3.2.4 Simplified Single Point Test 3.2.4.1 Stable Point LIT Deliverability Equation 3.2.4.2 AOFP Calculation With Single Point Test Method 3.2.5 Schematic Diagram of Calculating Pressure Differential for Various Test Methods 3.3 TREATMENT OF DELIVERABILITY TEST DATA 3.3.1 Two Deliverability Equations 3.3.1.1 Exponential Deliverability Equation 3.3.1.2 LIT Equation 3.3.2 Difference between Two Deliverability Equations 3.3.2.1 If Gas Flow Rate of Tested Well During Testing is Higher Than 50% of AOFP, Calculation Results of Two Deliverability Equations are Similar 3.3.2.2 Greater Error Generates from Exponential Deliverability Equation if Pressure Differences are Small of all Test Points 3.3.3 Three Different Pressure Expressions of Deliverability Equation 3.4 PARAMETER FACTORS INFLUENCING GAS WELL DELIVERABILITY 3.4.1 Expressions of Coefficients A And B in Deliverability Equation of a Well In Infinite Homogeneous Reservoir 3.4.1.1 Analysis of Expression of A [Equation (3.22)] 3.4.1.2 Analysis of Expression of B [Equation (3.23)] 3.4.2 Deliverability Equation When Gas Flow Entering into Pseudo-steady State 3.5 SHORT-TERM PRODUCTION TEST COMBINED WITH MODIFIED ISOCHRONAL TEST IN GAS WELLS 3.5.1 Pressure Simulation of Tested Wells 3.5.2 Improvement of AOFP Calculation Methods In Modified IsochronalTest 3.5.2.1 Classical Method 3.5.2.2 Improved Calculation Method 3.5.2.3 Comparison of Two Calculation Methods 3.6 STABLE POINT LAMINAR-INERTIAL-TURBULENT (LIT) DELIVERABILITY EQUATION 3.6.1 Background of Bringing Forward Stable Point LIT Deliverability Equation 3.6.1.1 Puzzles in Determining Gas Well Deliverability by Classical Methods 3.6.1.2 Existing Problems of Classical Methods 3.6.2 Stable Point LIT Deliverability Equation 3.6.2.1 Characteristics of New-Type Deliverability Equation 3.6.2.2 The New Method is Supplement and Improvement of The Original Classical Deliverability Test Method 3.6.3 Theoretical Deduction and Establishment of Stable Point LIT Deliverability Equation 3.6.3.1 Classification of Parameters Influencing Coefficients A and B 3.6.3.2 Determination of Deliverability Coefficient kh and Establishment of Initial Deliverability Equation 3.6.4 Field Examples 3.6.4.1 Application of Initial Stable Point LIT Equation in Well Kl-205 3.6.4.2 LIT Equation Established in SLG Gas Field 3.6.5 Methods of Establishing Dynamic Deliverability Equation 3.6.5.1 Initial stable point LIT equation is established firstly 3.6.5.2 Establishment of dynamic deliverability equation 3.6.5.3 Deliverability decline process in gas wells 3.6.6 Stable Point LIT Equation of Horizontal Wells 3.6.6.1 Theoretical Deduction of Stable Point LIT Equation for Horizontal Wells 3.6.6.2 Establishment the Initial Stable Point LIT Deliverability Equation for Horizontal Wells 3.6.6.3 Method of Establishing Dynamic Deliverability Equation 3.7 PRODUCTION PREDICTION IN DEVELOPMENT PROGRAM DESIGNING OF GAS FIELDS 3.7.1 Deliverability Prediction of Wells with Available Well Test Data 3.7.1.1 Determining Gas Well Flow Rate with Reasonable Producing Pressure Differential 3.7.1.2 Gas Flow Rate is Determined by Intersection of the Inflow Performance Relationship and Outflow Performance Relationship Curves 3.7.1.3 Determining Deliverability During the Process of Formation Pressure Depletion 3.7.1.4 Other Limitations for Gas Flow Rate 3.7.2 Deliverability Prediction of Production Wells in Development Program Designing 3.7.2.1 Establishing the Deliverability Equation of the Whole Gas Field 3.7.2.2 Plotting Distribution Map of kh Value over the Whole Gas Field and Determination of kh Value at Well Point 3.7.2.3 Calculating Rational Flow Rate of Planned Wells in the Development Program by Deliverability Equation 3.8 DISCUSSION ON SEVERAL KEY PROBLEMS IN DELIVERABILITY TEST 3.8.1 Design of Deliverability Test Points 3.8.1.1 Design of Flow Rate Sequence 3.8.1.2 Stabilization of Gas Flow Rate 3.8.1.3 Selection of Duration For Each Test Point 3.8.2 Why Calculated AOFP Sometimes is Lower Than Measured Wellhead Flow Rate 3.8.3 Existing Problems in Calculating AOFP by Backpressure Test Method 3.8.3.1 Backpressure Test for Homogeneous Formations 3.8.3.2 Backpressure Test for Fractured Wells in Channel Homogeneous Formation 3.8.4 Method and Analysis of Single-Point Deliverability Test and its Error 3.8.4.1 Single-Point Deliverability Test 3.8.4.2 Two Examples of AOFP Calculation Formulae for Single-Point Test in Development Areas of Gas Field 3.8.4.3 Some Examples of AOFP Calculation Formulae for Single-Point Test Method for Exploration Wells 3.8.4.4 Errors Analysis of Single-Point Deliverability Test Method 3.8.5 Deliverability Test without Any Stable Flow Points 3.8.6 Discussion on Wellhead Deliverability 3.8.7 Manually Calculating the Coefficients A and B in Deliverability Equation and AOFP 3.8.7.1 Data Acquisition 3.8.7.2 Establishment of Transient Deliverability Equation 3.8.7.3 Establishment of Stabilized Deliverability Equation 3.8.7.4 Calculating AOFP 3.9 Summary Chapter 4 Gas Reservoir Characteristics with Pressure Gradient Method 4.1 PRESSURE GRADIENT ANALYSIS OF EXPLORATION WELLS IN THE EARLY STAGE AND SOME FIELD EXAMPLES 4.1.1 Collection and Processing of Pressure Data 4.1.2 Pressure Gradient Analysis 4.2 CALCULATION OF GAS DENSITY AND PRESSURE GRADIENT UNDER FORMATION CONDITIONS 4.3 PRESSURE GRADIENT ANALYSIS DURING DEVELOPMENT OF A GAS FIELD 4.4 SOME KEY POINTS IN PRESSURE GRADIENT ANALYSIS 4.4.1 Accuracy of Acquired Pressure Data 4.4.2 Pressure Gradient Analysis should be Combined Closely with Geologic Research 4.4.2.1 The Area-Division of the Reservoir Provided by Pressure Gradient Analysis should be Supported by the Relevant Geological Basis 4.4.2.2 Analysis of Pressure Gradient Characteristics Provides Supporting Information for Validating Reserves Calculation Results 4.4.2.3 Analysis of Pressure Gradient Provides Basic Parameters for the Designing of Development Program 4.5 ACQUISITION OF DYNAMIC FORMATION PRESSURE AFTER A GAS FIELD HAS BEEN PUT INTO DEVELOPMENT 4.5.1 Dynamic Production Indices During Production of a Gas Field 4.5.2 Several Formation Pressures with Different Meanings 4.5.2.1 Measured Average Formation Pressure 4.5.2.2 Formation Pressure Determined by Deduction Based on Dynamic Model 4.5.2.3 Calculation of Formation Pressure at Gas Drainage Boundary pe 4.5.2.4 Other Frequently Used Formation Pressure Concepts 4.5.3 Performance Analysis with Dynamic Formation Pressures 4.5.3.1 Research on Reservoir Division 4.5.3.2 Dynamic Variation Analysis of Pressure Gradient Line Chapter 5 Gas Reservoir Dynamic Model and Well Test 5.1 INTRODUCTION 5.1.1 Static and Dynamic Models of Gas Reservoir 5.1.1.1 Geological Modeling of Gas Reservoirs 5.1.1.2 Dynamic Model of Gas Reservoirs and Gas Wells 5.1.2 Pressure History of a Gas Well Symbolizes the Life History of it 5.1.2.1 Different Pressure Histories Exist Under Different Reservoirs and/or Different Well Completion Conditions 5.1.2.2 Pressure History Trend of Gas Well is Determined by Reservoir Conditions 5.1.2.3 Main Approach to Confirm Reservoir Dynamic Model is Pressure History Match Verification 5.1.3 Study Characteristics of Reservoir Dynamic Model Based on Characteristics of Transient Well Test Curves 5.1.3.1 Different Portions of Transient Pressure Curve Reflect Characteristics of Different Zones of the Reservoir 5.1.3.2 Pressure Derivative Curve is the Main Basis in Identifying Reservoir Characteristics 5.1.3.3 “Graphics Analytical Method” used to Identify Reservoir Dynamic Mode 5.2 PRESSURE CARTESIAN PLOT-PRESSURE HISTORY PLOT 5.2.1 Content and Drawing of Gas Well Pressure History Plot 5.2.1.1 Preprocessing and Data Examination of Gas Well Pressure History Records 5.2.1.2 Pressure History Plot of Gas Well 5.2.2 Information About Formation and Well Shown in Pressure History Plot 5.2.2.1 Pressure History Plot During DST Of Natural Flow Gas Well 5.2.2.2 Pressure History Plot during DST of Low Production Rate Gas Well 5.3 PRESSURE SEMILOG PLOT 5.3.1 Several Semilog Plots 5.3.1.1 Pressure Drawdown Analysis Plot 5.3.1.2 Horner Plot 5.3.1.3 MDH Plot 5.3.1.4 Superposition Function Plot 5.3.2 Semilog Plot used in Analysis by Well Test Interpretation Software 5.3.2.1 Model Diagnosis in Early Interpretation Process 5.3.2.2 Verification of Match Analysis Results of Well Test Model 5.4 LOG-LOG PLOT AND MODEL GRAPH OF PRESSURE AND ITS DERIVATIVE 5.4.1 Log-log Plots and Type Curves for Modern Well Test Interpretation 5.4.1.1 Type Curve Analysis is the Core of Modern Well Test Interpretation 5.4.1.2 Some Common Log-Log Type Curves 5.4.2 Typical Characteristic Curves―Model Graphs for Well Test Analyses 5.5 CHARACTERISTIC DIAGRAM AND FIELD EXAMPLES OF TRANSIENT WELL TEST IN DIFFERENT TYPES OF RESERVOIRS 5.5.1 Characteristic Diagram (Model Graph M-1) and Field Examples of Homogeneous Formations 5.5.1.1 Homogeneous Formations in Gas Fields 5.5.1.2 Positioning Analysis 5.5.1.3 Classified Model Graphs for Positioning Analysis of Homogeneous Formations 5.5.1.4 Field Examples 5.5.2 Characteristic Graph of Double Porosity System (Model Graphs M-2 and M-3) and Field Examples 5.5.2.1 Composition and Flow Characteristics of Double Porosity System 5.5.2.2 Several Influencing Factors in Acquiring Parameters of Double Porosity System 5.5.2.3 Conditions for High-Quality Data Acquisition and Some Field Examples 5.5.3 Characteristic Graph of Homogenous Formation with Hydraulic Fractures (Model Graphs M-4 and M-5) and Field Examples 5.5.3.1 Creation and Retention Mechanism of Hydraulic Fracture 5.5.3.2 Curve Characteristics of Well Connecting with a High Conductivity Vertical Fracture 5.5.3.3 Flow Characteristics of in Fracture with Uniform Flow 5.5.3.4 Vertical Fracture with Finite Conductivity 5.5.3.5 Fracture Skin Factor and its Effect 5.5.4 Characteristic Diagram of Wells with Partial Perforation (Model Graph M-6) and Field Examples 5.5.4.1 Geological Background of Well Completion with Partial Perforation 5.5.4.2 Flow Model in Cases of Partial Perforation 5.5.4.3 Field Examples 5.5.5 Characteristic Diagram and Field Examples of Composite Formation (Model Graphs M-7 and M-8) 5.5.5.1 Principles for Evaluation of Type of Reservoir Boundary 5.5.5.2 Geological Conditions of Composite Formations 5.5.5.3 Model Graph of Composite Formation 5.5.5.4 Analysis of Field Examples 5.5.6 Characteristic Graph of Formations with No-Flow Boundaries (Model Graphs M-9-M-13) and Field Examples 5.5.6.1 Geological Background 5.5.6.2 Flow Model Graph of a Well with No-Flow Outer Boundary 5.5.7 Characteristic Graph and Field Examples of Fissured Zone with Boundaries (Model Graphs M-14 and M-15) 5.5.7.1 Strip-Like Fissured Zone with Directional Permeability 5.5.7.2 Beaded Fissured Bands 5.5.7.3 Complex Fissured Zone 5.5.8 Characteristic Graph and Field Examples of Condensate Gas Wells 5.5.8.1 Geological Background and Focused Problems 5.5.8.2 Model Graphs and Field Examples of Transient Test in Condensate Gas Well 5.5.9 Characteristic Graph of Horizontal Wells (Model Graph M-16) and Field Examples 5.5.9.1 Geological and Engineering Background 5.5.9.2 Typical Well Test Model Graph 5.6 SUMMARY Chapter 6 Interference Test and Pulse Test 6.1 APPLICATION AND DEVELOPMENT HISTORY OF MULTIPLE-WELL TEST 6.1.1 Application of Multiple-Well Test 6.1.1.1 To Identify Formation Connectivity between Wells 6.1.1.2 To Confirm the Sealing of Faults 6.1.1.3 To Estimate Interwell Connectivity Parameters 6.1.1.4 To Identify the Vertical Connectivity of Reservoir 6.1.1.5 To Study Formation Anisotropy 6.1.1.6 To Study the Reservoir Areal Distribution and to Confirm the Results of Reserves Estimation 6.1.2 Historical Development of Multiple-Well Test 6.1.2.1 Multiple-Well Test Development Abroad 6.1.2.2 Development of Multiple-Well Test in China 6.1.3 How to Perform and Analyze the Interference Test and Pulse Test 6.1.3.1 Factors Affecting Interference Pressure Acquisition 6.1.3.2 Dialectic Consideration for Performing Multiple-Well Test Research in a Region 6.2 PRINCIPLE OF INTERFERENCE TEST AND PULSE TEST 6.2.1 Interference Test 6.2.1.1 Test Methods 6.2.1.2 Parameter Factors Affecting Interference Pressure Response Value 6.2.1.3 Type Curve Interpretation Method for Interference Test Data 6.2.1.4 Characteristic Point Interpretation Method for Interference Test 6.2.2 Pulse Test 6.2.2.1 Pulse Test Method 6.2.2.2 Kamal’s Analysis Method for Pulse Test 6.2.2.3 Pulse Test Analysis by Conventional Interference Test Type Curve Methods 6.2.3 Multiple-Well Test Design 6.2.3.1 Principle of Multiple-Well Test Design 6.2.3.2 Multiple-Well Test Simulated Design 6.2.3.3 Make Multiple-Well Test Field Implementation Plan 6.3 FIELD EXAMPLES OF MULTIPLE-WELL TEST IN OIL AND GAS FIELD RESEARCH 6.3.1 Interference Test Research in JB Gas Field 6.3.1.1 Geological Conditions of JB Gas Field 6.3.1.2 Well Test Design and Operation 6.3.1.3 Test Results 6.3.1.4 Parameter Calculation 6.3.2 SLG Gas Field Interference Test Research 6.3.2.1 Overall Geological Conditions of Well Group of Interference Test 6.3.2.2 Interference Test Well Group Design and Implementation 6.3.2.3 Interpretation of Interference Test Data 6.3.2.4 To Identify Rational Well Spacing in SLG Gas Field by Interference Test Results 6.3.3 Gas Well Interference Test Study in Fault Block Y8 of SL Oil Field 6.3.4 Test Research on Connectivity between Injector and Producer in Fault Block 6.3.4.1 Research of Connectivity between Injector and Producer in ST Block 3, SL Oil Field 6.3.4.2 Research on Isolation of the Fault in Well Y18 Area of SL Oil Field 6.3.4.3 Efficiency Analysis of Injection in Fault Block B96 6.3.5 Comprehensive Evaluation of Multiple-Well Tests in KL Palaeo-Burial Hill Oil Field 6.3.5.1 Overall Geological Condition of KL Oil Region 6.3.5.2 Test Arrangement and Achieved Results 6.3.5.3 Analyzing the Characteristics of Formation Dynamic Model with Multiple-Well Test Results 6.4 SUMMARY Chapter 7 Coalbed Methane Well Test Analysis 7.1 COALBED METHANE WELL TEST 7.1.1 Function of Coalbed Methane Well Test in Coalbed Methane Reservoir 7.1.1.1 To Obtain Effective Permeability of Fissures or Cleats in Coalbed 7.1.1.2 To Obtain Average Reservoir Pressure 7.1.1.3 To Analysis Damage and Improvement of Coalbeds 7.1.1.4 To Evaluate Fracturing Effects 7.1.1.5 To Identify Coalbed Connectivity and Calculate Connectivity Parameters 7.1.1.6 To Determine of Pore Volume of Coalbed 7.1.1.7 To Analysis the Development Direction of Fissures 7.1.1.8 To Detect the Flow Boundaries in Coalbed 7.1.2 Differences between Coalbed Methane Well Test and Common Gas Well Test 7.1.2.1 Fluid Seen During Coalbed Methane Well Testing Is Often Water 7.1.2.2 Do Not Show Flow Characteristics of the Double Porosity Medium 7.1.2.3 Purpose and Analysis Methods Depend On Production Stages 7.2 FLOW MECHANISM AND WELL TESTING MODELS IN A COALBED 7.2.1 Structural Characteristics of a Coalbed and Flow of Coalbed Methane 7.2.1.1 Structure of Coalbed and Reserve of Methane 7.2.1.2 Flow Process in Coalbed Methane Production 7.2.2 Typical Dynamic Models of Coalbed Methane Well Test 7.2.3 Water Single-Phase Flow Characteristics and Data Interpretation Methods 7.2.4 Single-Phase Flow of Methane Desorption and Well Test Analysis Method 7.2.4.1 Coalbed Conditions 7.2.4.2 Flow Equation 7.2.4.3 Analyzing Coalbed Methane Well Test Data by Conventional Method 7.2.4.4 Characteristics of Well Test Curves When Desorption Happens 7.3 INJECTION/FALLOFF WELL TEST METHOD FOR COALBED METHANE WELLS 7.3.1 Equipment and Technology for Injection/Falloff Well Testing 7.3.1.1 Test String 7.3.1.2 Measuring Instruments 7.3.1.3 Water Injection Pump 7.3.1.4 Testing Process 7.3.2 Well Test Design of Injection/Falloff 7.3.2.1 Selection of Shut-In Mode 7.3.2.2 Calculation of Injection Pressure 7.3.2.3 Calculation of Water Injection Rate 7.3.2.4 Determination of Water Injection Volume 7.3.2.5 Determination of Influence Radius and Injection Duration 7.3.2.6 Effect of Coalbed Elastoplasticity 7.3.3 Data Examination and Analysis Methods of Injection/Falloff Well Testing 7.3.3.1 Variable Wellbore Storage Effect in Injection/Falloff Test Process 7.3.3.2 Inspection of Abnormal Changes of Test Curves 7.3.3.3 Comments on Data Examination and Analysis 7.4 ANALYSIS AND INTERPRETATION OF INJECTION/FALLOFF TEST DATA 7.4.1 Interpretation Methods 7.4.1.1 Model Types 7.4.1.2 Interpretation Procedure 7.4.2 Real Field Example 7.4.2.1 Well Ex 1-A Coalbed Methane Well Completed with Fracturing 7.4.2.2 Well Ex 2-A Perforated Completion Coalbed Methane Well 7.5 SUMMARY Chapter 8 Gas-field Production Test and Dynamic Gas Reservoir Description 8.1 PRODUCTION TEST IN SPECIAL LITHOLOGIC GAS FIELDS IN CHINA 8.1.1 Special Lithologic Gas Field in China 8.1.2 Production Test: An Effective Way to Solve Problems in Development of Special Lithologic Gas Reservoirs 8.1.3 Procedure of Production Test in Gas Wells 8.1.4 Dynamic Reservoir Description Based on Production Test Data of Gas Wells 8.2 DYNAMIC GAS RESERVOIR DESCRIPTION IN DEVELOPMENT PREPARATORY STAGE OF JB GAS FIELD 8.2.1 Geological Conditions of JB Gas Field 8.2.2 Focuses of the Problems 8.2.3 Dynamic Study at the Preparatory Stage of Gas Field Development 8.3 SHORT-TERM PRODUCTION TEST AND EVALUATION OF GAS RESERVOIR CHARACTERISTICS IN KL-2 GAS FIELD 8.3.1 Geological Condition 8.3.2 Procedure and Result