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Dedication |
6 |
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Preface |
8 |
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Acknowledgements |
10 |
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Contents |
12 |
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About the Author |
20 |
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Chapter 1: Introduction to the Oil Industry and Oil Show Evaluation: A Personal Retrospective |
21 |
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1.1 Introduction and Vocabulary of Oil and Gas |
22 |
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1.2 The Art of Exploration |
27 |
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1.2.1 A History of Drilling and Exploration |
28 |
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1.2.2 Generational Challenges and Evolving Technology |
30 |
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1.2.3 Some Personal Experiences in Learning About Seals and Shows |
31 |
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1.2.4 The Art of Exploration: Plays Versus Prospects and Getting Proper Experience Early |
34 |
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1.2.5 Creaming Curves and New Plays Versus Prospects: Challenging the ‘Peak oil’ Paradigm |
35 |
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1.2.6 Looking at Rocks, Dealing with People and Your Learning Curve |
38 |
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1.2.7 Break from Paradigms: Believe in Yourself and Your Data |
40 |
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1.2.8 Pay Attention to the Fluids and the Key Well Concept |
41 |
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1.2.9 The Value of Teams, Peer Assists and Risk Assessment |
43 |
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1.2.10 The Need to Get It Right Needs to Be Balanced by a Need for Speed |
44 |
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1.2.11 Looking for the NULF (Nasty, Ugly, Little Fact) to Break Paradigms |
44 |
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1.2.12 Pay Attention to Tight Rocks with Oil and Gas Shows |
46 |
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1.2.13 You Never Have Enough Data, But Perseverance Pays Off |
47 |
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1.3 Some Background on Seismic |
48 |
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1.4 New Tools: Advances in Migration Modeling and Shows Calibration |
55 |
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1.4.1 Spider Maps to 3D Models |
56 |
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1.4.2 Some Examples of Model Development and Visualization |
58 |
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1.5 Summary |
62 |
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References |
62 |
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Chapter 2: The Basics of Traps, Seals, Reservoirs and Shows |
66 |
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2.1 The Petroleum System: Primary, Secondary Migration, and ‘Unconventional’ Exploration |
67 |
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2.2 Traps, Porosity, Spill Points and Seals |
68 |
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2.2.1 You Don’t Need to Know Why a Trap Exists If You Can Figure Out Where It Is from the Test and Show Data |
76 |
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2.3 Assessing Risk: Thinking About Seals, Structure and Reservoir Quality |
79 |
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2.3.1 Making the Right Maps |
82 |
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2.3.2 Some Thoughts on Stratigraphic Traps |
85 |
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2.4 The Basics of Rock Properties, Free Water Levels, Buoyancy Pressure and Hydrocarbon Shows |
90 |
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2.4.1 Porosity |
90 |
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2.4.2 Buoyancy Pressure (Pb), Pressure vs. Depth Plots, Free Water Levels and Water Saturation |
93 |
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2.4.3 Water and Hydrocarbon Saturations and Height Above Free Water Plots |
95 |
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2.4.4 Oil-Water Contacts, Top of Transition Zones vs. FWL and Relative Permeability |
96 |
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2.4.5 Permeability |
99 |
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2.4.6 Waste Zones |
99 |
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2.4.7 Oil Show Types |
101 |
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2.4.8 Kerogen-Rich Source Rocks |
104 |
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2.4.9 Thinking Like a Molecule |
105 |
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2.5 Summary |
105 |
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References |
106 |
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Chapter 3: Drilling, Mud-Logging, Wireline Logs and Cores |
110 |
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3.1 Historical Context Around Understanding Shows and Drilling Wells |
111 |
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3.1.1 Horizontal Wells and Multi-Stage Fracturing |
113 |
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3.1.2 East vs. West: Evolution of Different Evaluation Techniques |
114 |
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3.1.3 Seeps |
116 |
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3.1.4 Drilling with Mud |
117 |
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3.1.5 Wellbore Design, Pressures and Rig Safety |
118 |
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3.1.6 Background on Muds, Mud-Weights and Circulation Time |
119 |
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3.2 Mud Logs, Gasses and Cuttings Descriptions |
120 |
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3.2.1 The Mud Log |
120 |
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3.2.2 Analyzing Mud Gasses: Wet to Light Gas Ratio Analysis |
122 |
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3.2.3 Wellbore Flushing and Over and Underbalanced Drilling |
125 |
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3.2.4 Cuttings and Oil Shows |
129 |
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3.2.4.1 Residual Shows |
129 |
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3.3 Basics of Well Logs |
132 |
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3.3.1 Well log Formats: Digital vs. Raster |
132 |
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3.3.2 The Well Header and Common Logs |
133 |
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3.3.3 Common Log Displays and the Basics of Log Interpretation |
134 |
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3.3.4 Gamma Ray (GR) and Spontaneous Potential (SP) Logs |
140 |
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3.3.5 Porosity Logs, Volume of Shale Calculations and Total vs. Effective Porosity |
141 |
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3.3.6 Quick Look for Gas Effect and Permeability from Resistivity Profiles |
143 |
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3.3.7 Calculating Lithology |
144 |
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3.4 Capturing and Interpreting Core Data |
145 |
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3.4.1 Core Data |
145 |
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3.4.2 Saturation Changes in Coring |
146 |
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3.5 How to Miss Good Hydrocarbon Shows and Case Histories |
148 |
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3.5.1 Ways to Miss Hydrocarbon Shows |
148 |
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3.5.2 Suppressed Resistivity and ‘Hot Gamma Ray’ Reservoirs |
148 |
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3.5.3 Case History 1: Russian River SE Field: “Hot” Dolomite and by-Passed Pay, Williston Basin, Montana |
149 |
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3.5.4 Case History 2: Using Gas Wetness mud log Analysis to Discover of a New Turbidite Oil Play Fairway, Eocene Dharvi Dungar Formation, Barmer Basin, India |
152 |
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3.5.4.1 Acknowledgements and Introduction |
152 |
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3.5.4.2 Regional Setting |
154 |
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3.5.4.3 Summary and Impact |
156 |
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3.6 Summary |
156 |
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3.6.1 The Worst Thing I Ever Heard a Mud Logger Say |
160 |
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References |
160 |
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Chapter 4: Understanding Seals, Pressures and Hydrodynamics |
163 |
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4.1 Basic Pressure Terms, Uses and Pressure Data Collection |
164 |
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4.1.1 Why Look at Seals from the Standpoint of Pressures and Hydrodynamics? |
164 |
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4.1.2 Some Good References |
165 |
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4.1.3 Pore Pressure |
167 |
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4.1.4 Recognizing Seals on Pressure-Depth Plots and Understanding mud Weights |
172 |
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4.1.5 Tools and Data Capture for Pressure Analysis |
176 |
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4.1.5.1 Data Reporting Formats |
178 |
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4.2 Understanding Facies and Fault Seals Qualitatively |
182 |
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4.2.1 Seals Overview: Facies and Fault Seals |
182 |
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4.2.1.1 Seal Quality, Pressures and Time |
183 |
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4.2.2 Fault Seals |
188 |
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4.2.2.1 Fault Traps, Gouge and Juxtaposition Analysis |
188 |
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4.2.2.2 Stress Direction: Borehole Breakout |
195 |
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4.2.2.3 Testing Fault Models with Shows |
197 |
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4.3 Building and Interpreting Pressure Vs. Depth Plots and Hydrodynamic Flow |
199 |
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4.3.1 The Basics of Pressure-Depth Plots and Recognition of Hydrodynamic Flow |
199 |
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4.3.2 Making Potentiometric Surface Maps and Modeling Hydrodynamic Entrapment |
205 |
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4.3.3 Modeling Hydrodynamic Tilt and Migration Using Potentiometric Surface Maps |
207 |
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4.3.4 A Practical Example of Hydrodynamic Tilting Using Trinity Software |
209 |
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4.3.5 Example of Tilted Contacts in an Overpressured Environment |
210 |
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4.3.6 Building Your Own Hydrodynamic Maps: A Bit More Theory Behind Migration and Hydrodynamics: The U-V-Z Method |
212 |
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4.3.6.1 A Note on the Value of Z in Many Petroleum Systems Software Packages |
213 |
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4.3.6.2 Hubbert’s Full Equation with Seal Capacity Added |
214 |
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4.3.7 Perched Water—Another Problem That Can Look Hydrodynamic |
215 |
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4.3.7.1 Ormen-Lange Field, Norway—Perched or Tilted? |
218 |
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4.4 High Pressure Systems, Pressure Regressions and Fracture Seal Breaching |
221 |
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4.4.1 Maps of Over Pressure |
222 |
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4.4.2 Deep Overpressure and Log and Seismic Methods of Prediction |
224 |
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4.4.3 Pressure Regressions and Fracture Gradients- Casing Design, Room for Accumulations and Enhanced Seal Capacity |
228 |
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4.4.4 Bigger Isn’t Always Better-the Role of Pressures and Centroids in Fracture Seal Breach and Exploration Failure |
233 |
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4.4.5 Summary of Part IV |
236 |
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4.5 Case Histories |
237 |
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4.5.1 Temsah Field: 25 Years to Recognition of a Tilted Gas-Water Contact |
239 |
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4.5.2 Deep Nile Delta Play Opener: Pressures and Shows Identified the Play |
242 |
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4.6 Summary |
245 |
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References |
246 |
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Chapter 5: Quantifying Seals and Saturations: Capillary Pressure, Pseudo-capillary Pressure and Quantitative Show Assessment |
251 |
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5.1 The Fundamentals of Capillary Pressure |
252 |
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5.1.1 The Importance of Understanding Capillary Pressure |
252 |
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5.1.2 Fluid Potential (Entrapment) Maps Using Capillary Pressure Seals |
253 |
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5.1.3 Capillary Pressure |
254 |
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5.1.3.1 Mercury Injection Capillary Pressure Analysis |
257 |
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5.1.4 Estimating Height Above Free Water from Capillary Pressure Data |
263 |
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5.1.5 Relative Permeability, Water Cut and Oil-Water Contacts |
264 |
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5.1.6 Imbibition Curves and Residual Saturations |
267 |
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5.1.7 Summary |
268 |
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5.2 Flow Units, Winland Plots, Pseudo-capillary Pressure Curves and Mapping Seals |
269 |
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5.2.1 Flow Units and Winland Plots |
270 |
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5.2.2 Pseudo-capillary Pressure Curves |
275 |
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5.2.3 Making a Seal Capacity Estimate When You Do Not Have a Pseudo-capillary Pressure Spreadsheet |
278 |
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5.2.3.1 Weyburn Field Example |
279 |
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5.2.4 Migration with Seals: Examples from Aneth Field Area, Utah-Colorado |
279 |
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5.2.5 Migration with Both Fault Seals and Hydrodynamics-Temsah Field, Egypt |
289 |
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5.2.6 Summary |
290 |
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5.3 Show Types and Quantitative Assessment |
291 |
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5.3.1 Building and Visualizing a Shows Database |
296 |
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5.3.2 Summary |
299 |
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5.4 Case Histories |
299 |
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5.4.1 Cases 1–4: October Field, Egypt |
299 |
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5.4.1.1 Case 1: Underestimating a Field Size—Failure to Get the Free Water Level Right, GS 184 Field, October Field Complex, Egypt |
301 |
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5.4.1.2 Case 2: Cap Pressure Analysis Leads to Deeper Oil-Water Contact, October Field, Egypt |
306 |
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5.4.1.3 Case 3: Capillary Pressure and Sample Shows in Dry Hole with by-Passed Pay Lead to Updip oil Discovery, October Field, Egypt |
311 |
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5.4.1.4 Case 4: “J” Platform Oil Discovery-Drilling Updip of Residual Oil, October Field, Egypt |
314 |
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5.4.1.5 Case History 5: Buzzard Field, United Kingdom. Missing a Key Oil Show |
316 |
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5.4.1.6 Case History 6: Hugoton Field: Giant re-Migration Along Residual Migration Pathway |
318 |
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5.4.1.7 Case History 7: West Siberian Basin, Russia: Perhaps the World’s Largest Residual Migration Pathway |
322 |
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5.5 Summary |
327 |
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References |
329 |
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Chapter 6: Basic Log Analysis, Quick-Look Techniques, Pitfalls and Volumetrics |
333 |
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6.1 Overview |
334 |
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6.2 The Archie Equation and Finding Rw |
335 |
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6.2.1 Archie Equation Limits Due to Shaliness |
335 |
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6.2.2 Archie Equation Steps |
336 |
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6.2.3 Finding Rw |
337 |
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6.3 Porosity Logs and Calculations |
338 |
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6.3.1 Sonic Log Porosity |
340 |
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6.3.2 Density Log Porosity |
340 |
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6.3.3 Porosity from Combination Neutron-Density Logs |
342 |
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6.4 Some Quick Look Techniques: Pickett and Buckles Plots |
342 |
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6.4.1 Pickett Plots |
343 |
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6.4.2 Buckles Plots and Bulk Volume Water (BVW) |
344 |
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6.5 Pattern Recognition of Pay |
345 |
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6.5.1 Example 1: Eocene Wilcox Sandstone |
346 |
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6.6 Residual Shows on Logs |
347 |
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6.7 Pitfalls: Clays, Shales, Laminated Pays |
348 |
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6.7.1 Low Resistivity-Low Contrast Pays (LCLR) |
350 |
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6.7.2 Using Micro-resistivity and NMR Logs in Shaly and Difficult Pay Zones |
352 |
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6.7.2.1 NMR Logs |
352 |
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6.7.3 More Pitfalls: Clays, Conductive Minerals and Formation Damage |
356 |
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6.8 A Note on Calculating Reserves |
360 |
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6.9 Summary |
360 |
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References |
362 |
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Chapter 7: Using Fluid Inclusion Data in Exploration |
366 |
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7.1 Introduction and Overview of Fluid Inclusions |
367 |
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7.1.1 The Reality of Migration: It Is Complicated! |
369 |
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7.2 Conventional Fluid Inclusion Analysis |
370 |
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7.2.1 Using Microthermometry Data and Identifying Hydrocarbon Types and Salinities |
372 |
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7.3 Bulk Fluid Inclusion Analysis with FIS |
378 |
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7.3.1 Proximity to Pay |
382 |
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7.3.2 Bacterial and Thermal Alteration |
385 |
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7.3.3 A Note on Drill Bit Metamorphism (DBM) |
387 |
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7.4 FIS Interpretation Examples |
389 |
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7.4.1 Northwest Coast of Australia |
390 |
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7.4.2 Prospect Ranking |
391 |
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7.4.3 Barents Sea |
391 |
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7.4.4 Sogn Graben |
392 |
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7.4.5 Unconventional Well Performance-Mancos Shale, Utah |
394 |
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7.4.6 Example of Detecting Oil Shows Missed on Mud Logs: Barmer Basin, India |
396 |
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7.5 Summary |
398 |
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References |
398 |
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Chapter 8: Shows and Geochemistry: Extracting More Information from Source Rocks and Hydrocarbons |
401 |
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8.1 Introduction |
402 |
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8.2 Source Rock Quality and Maturation |
403 |
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8.2.1 The Language of Source Rocks |
403 |
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8.2.2 Rock Eval Pyrolysis |
404 |
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8.2.3 Source Rock Quality |
405 |
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8.2.4 Maturation and Source Rock Type |
408 |
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8.2.4.1 Maturation and Rock Eval Numbers: What you see is not What you Had |
412 |
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8.2.4.2 Delta LogR and Resistivity Mapping |
418 |
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8.2.5 Building Maturation Models and Understanding Heat Flow |
420 |
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8.2.5.1 Geothermal Gradient and Heat Flow |
422 |
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8.2.5.2 Heat Flow Modelling |
424 |
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8.2.5.3 An Example of Basement Control on Heat Flow and Maturation-Bakken Formation, Williston Basin |
427 |
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8.2.5.4 1-D Burial Models |
429 |
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8.2.6 Summary: Source Rock Quality and Maturation |
434 |
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8.3 Rig Data Collection: Headspace gas and mud Isotubes |
435 |
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8.3.1 Summary |
443 |
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8.4 Some Source Rock Play Screening Criteria |
444 |
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8.4.1 Sweet Spots |
447 |
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8.4.1.1 A Note on Calculating Volumes of Oil or Gas in Shale |
447 |
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8.5 Oil to Source Correlations |
450 |
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8.5.1 Examples of Utility of Understanding Basic Oil and Rock Geochemistry Correlations |
451 |
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8.5.1.1 Nile Delta, Egypt |
452 |
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8.5.1.2 Barmer Basin, India |
454 |
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8.5.2 A Case History of Migration Modeling from Oil to Source Correlations: Cutbank Field, Montana |
456 |
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8.6 Summary |
459 |
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References |
459 |
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Chapter 9: Building and Testing Migration Models |
466 |
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9.1 The Scale Challenge in Migration Modelling |
467 |
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9.2 Some Migration Concepts |
468 |
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9.3 Long Range Migration |
470 |
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9.4 Building Migration Models and Recognizing Limits with Risk Maps |
473 |
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9.5 Making Migration Risk Index Maps |
476 |
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9.6 Summary |
477 |
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References |
478 |
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Appendix A Common Conversion Equations and Fluid Classifications |
480 |
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References |
483 |
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Appendix B Constructing Winland Pore Throat Graphs in Excel |
484 |
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References |
486 |
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Appendix C Equations in Excel to Convert Mercury-Injection Capillary Pressure Data to Height Above Free Water |
487 |
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References, Capillary Pressure Conversion, Appendix B |
489 |
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Appendix D Equations in Excel to Make Pseudo-Capillary Pressure Curves |
490 |
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Example 2: Using R in Centimeters Instead of Mu |
494 |
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References |
494 |
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Appendix E Converting Paleogeographic Maps or Shapefiles in ARCGIS to Grids |
495 |
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