Operational Aspects of Oil and Gas Well Testing (eBook)

Front Cover 1
OPERATIONAL ASPECTS OF OIL AND GAS WELL TESTING 4
Copyright Page 5
CONTENTS 10
PREFACE 6
ACKOWLEDGEMENTS 8
CHAPTER 1. PURPOSE OF THE BOOK 32
CHAPTER 2. WELL TESTING RECOMMENDED PRACTICES 36
CHAPTER 3. WELL TEST OBJECTIVES 42
3.1 The Decision to Test 43
3.2 Mobilising Test Equipment 44
CHAPTER 4. SAFETY PROCEDURES 50
4.1 Breathing Apparatus 50
4.2 Certification, Service Testing and Safety Review 51
4.3 HAZOP Studies 52
4.4 Dangerous Substances 53
4.5 Daylight/High Visibility Working 54
4.6 Explosives 55
4.7 Fire Fighting Equipment 59
4.8 Gas Detection 60
4.9 Hydrogen Sulphide 61
4.10 Oil Spill Contingency 68
4.11 Restricted Access 68
4.12 Safety Meetings 69
4.13 Site Preparation 74
4.14 Start of Testing Operations 74
CHAPTER 5. JOB RESPONSIBILITIES DURING WELL TESTING 76
5.1 Barge Control Room (offshore) 76
5.2 Base Office 76
5.3 Boat Captain (Standby Vessel) 76
5.4 Cementers 77
5.5 Derrickman 77
5.6 Downhole Tool Operator 77
5.7 Driller 77
5.8 Drilling Engineer 77
5.9 Drilling Manager/Superintendent 78
5.10 Drilling Supervisor 78
5.11 Electric Wireline Engineer 78
5.12 Gauge Engineer 79
5.13 H2S Service Company Representative 79
5.14 Mud Engineer 79
5.15 Mud Logger 79
5.16 Petroleum / Reservoir Engineer 79
5.17 Production Testing Crew 79
5.18 Radio Operators 80
5.19 Slickline Operator 80
5.20 Sub-Sea Engineer 80
5.21 TCP Engineer 80
5.22 Test Engineer 80
5.23 Tool Pusher / OIM 81
CHAPTER 6. SPECIFIC WELL TEST OBJECTIVES 82
6.1 Boundaries 82
6.2 Flowrate 83
6.3 Maximum Rate Testing 83
6.4 Permeability 83
6.5 Reservoir Pressure 84
6.6 Samples 84
6.7 Zonal Contribution 86
CHAPTER 7. TEST DESIGN 88
7.1 Single Rate Oil Well Testing 89
7.2 Gas Well Tests 90
7.3 Transient Pressure Analysis 93
7.4 Artificial Lift Performance Testing 93
7.5 Aquifer Permeability and Mobility Testing 94
7.6 Bare Foot Testing 94
7.7 Slug or Closed ChamberTesting 94
7.8 Injectivity Testing 95
7.9 Open Hole Testing 96
7.10 Reservoir Limit Tests and Extended Well Tests 96
7.11 High Pressure High Temperature Testing (HP/HT) 97
7.12 Stimulation Technique – Evaluation 98
7.13 The Use of Tubing or Drill Pipe for the Test String 98
7.14 Two Valve Isolation 100
7.15 Well Preparation 100
7.16 Zonal Isolation 101
7.17 Well Test Planning Considerations / Checklist 101
CHAPTER 8. COMPLETION (PACKER) FLUIDS 102
8.1 Cost 102
8.2 Formation Pressure 102
8.3 Formation Temperature 103
8.4 Fluid Detenoration with Time 104
8.5 Overbalance Perforating 104
8.6 Underbalance Perforating 104
8.7 Skin Damage 104
CHAPTER 9. PERFORATING 106
9.1 Casing Gun Perforation 107
9.2 Through Tubing Perforation 107
9.3 Tubing Conveyed Perforation 108
9.4 Tubing Conveyed Perforating (TCP) Firing Heads 109
CHAPTER 10. DOWNHOLE TEST EQUIPMENT 118
10.1 DST (Drill Stem Test) Concepts 119
10.2 Bull Nose / Mule Shoe 130
10.3 Gauge (Bundle) Carriers 130
10.4 Debris Sub 131
10.5 Gun Release Sub 131
10.6 Shock Absorbers 131
10.7 Perforated Joint 131
10.8 Packers 132
10.9 Tubing Test Valve 133
10.10 Safety Joint 134
10.11 Hydraulic Jars 134
10.12 Relief Valve and Bypass Tool 134
10.13 Tester (Downhole Shut In) Valves 134
10.14 Surface Read Out (SRO) Subs 135
10.15 Radioactive Marker Sub 137
10.16 Drill Collars 137
10.17 Slip Joints 138
10.18 Reverse Circulation Valves 138
10.19 Cross Overs 139
10.20 Tubing / Drill Pipe Connections 139
10.21 IRIS 140
CHAPTER 11. PRESSURE GAUGES 148
11.1 Mechanical Gauges 148
11.2 Strain Gauges 149
11.3 Capacitance Transducer Gauges 149
11.4 Vibrating Crystal Transducer 150
11.5 Sapphire Crystal Transducer 150
11.6 Gauge Memory Sections 151
11.7 Memory Gauge Battery Packs 151
11.8 Surface Read Out (SRO) Gauges 152
11.9 Permanent and Semi-Permanent Gauges 152
11.10 Speciality Gauges 152
11.11 Calibration of Gauges 153
CHAPTER 12. SUB SEA EQUIPMENT 154
12.1 Sub Sea Test Tree ( SSTT) 154
12.2 Associated Sub Sea Equipment 158
12.3 DST Operating Criteria 161
12.4 Sub Sea Test Tree Disconnect 161
CHAPTER 13. SURFACE TEST EQUIPMENT 164
13.1 Surface Test Tree (Flowhead) 164
13.2 Coflexip Hoses 165
13.3 Rig Permanent Pipework 166
13.4 Hydraulic Surface Safety Valve 170
13.5 Surface Temporary Piping 170
13.6 Sand Trap 171
13.7 Sand Detection Equipment 171
13.8 Data Header 173
13.9 Choke manifold 173
13.10 Steam Heat Exchanger or Heater 179
13.11 Horizontal Separator 179
13.12 Vertical Separator 183
13.13 Metering 183
13.14 Electronic Surface Data Acquisition 189
13.15 Gauge Tank 189
13.16 Surge Tank 190
13.17 Transfer Pump 190
13.18 Gas Diverter Manifold 190
13.19 Oil Diverter Manifold 190
13.20 Burner Booms 193
13.21 Standard Oil Burners 193
13.22 Green Burners 194
13.23 Equipment Hook Up and Location 198
13.24 Flare Lines 199
13.25 Vent Lines 200
13.26 Relief Lines 201
13.27 Emergency Shutdown Systems 201
CHAPTER 14. WELL TESTING OPERATIONS 204
14.1 Equipment Checking 204
14.2 Operational Considerations for Equipment Layout 205
14.3 Flowmeter Calibration 207
14.4 Pressure Testing 207
14.5 Running the Test Tubing or Drill Pipe 208
14.6 Running and Setting the Packer 208
14.7 Choke Manipulation During Testing 209
14.8 Separator Operations 209
14.9 Production Problems 211
14.10 Well Control 220
CHAPTER 15. RESERVOIR FLUID BEHAVIOUR & SAMPLING OPERATIONS
15.1 Reservoir Fluid Behaviour 223
15.2 Sampling Programmes 226
15.3 Stable Flow 228
15.4 Downhole Sampling Conditions 229
15.5 Electric Line Sampling 229
15.6 Slickline Sampling 229
15.7 Transfer of Bottom Hole Samples 230
15.8 Test Tool Sampling 230
15.9 Reverse Circulation Sampling 231
15.10 Surface Sampling Points 232
15.11 Monophasic Surface Sampling 233
15.12 Recombination Sampling 234
15.13 Labelling of Samples 235
15.14 Storage and Disposal of Samples 236
CHAPTER 16. GAS, OIL & WATER MEASUREMENTS AND ANALYSIS
16.1 Gas Measurements and Analysis 238
16.2 Oil Measurements and Analysis 239
16.3 Water Measurements and Analysis 240
CHAPTER 17. REPORTING 242
17.1 Daily Reporting From The Wellsite 242
17.2 Final Well Test Report 244
CHAPTER 18. COIL TUBING AND NITROGEN 246
18.1 Coiled Tubing Equipment 246
18.2 Uses of Coil Tubing 248
18.3 Typical Coil Tubing Operating Procedures 250
18.4 Uses of Nitrogen 251
18.5 Uses of the Coil Tubing Nitrogen Combination 255
CHAPTER 19. STIMULATION 258
19.1 Responsibilities 258
19.2 Safety 258
19.3 Stimulation by Acid 259
19.4 Stimulation by Fraccing 260
CHAPTER 20. APPENDICES 266
Appendix A. Radius of Investigation Calculation 266
Appendix B. Well Test Planning Considerations – Check List 268
Appendix C. Choke Performance Equations 277
Appendix D. Separator Calculations 279
Appendix E. Selection of DST Tubulars 281
Appendix F. Estimation of Pressure Loss From Tubing Flow 282
Appendix G. Temperature Effects on Tubulars 284
Appendix H. Pressure Effects on Tubulars 285
Appendix I. Example – Detailed Well Test Programme 289
Appendix J. Testing & Related Services Contractors Web Sites
Appendix K. Simulator Products 345
INDEX 348