Electromagnetic Well Logging: Models for Mwd / Lwd Interpretation and Tool Design

ISBN-13: 9781118831038 / Angielski / Twarda / 2014 / 632 str.

Wilson Chin

Opis

Almost all publications on borehole electromagnetics deal with idealizations that are not acceptable physically, and unfortunately, even these models are company proprietary. On the other hand, -exact models- are only available through detailed finite element or finite difference analysis, and more often than not, simply describe case studies for special applications. In either case, the models are not available for general use and the value of the publications is questionable. This new approach provides a rigorous, fully three-dimensional solution to the general problem, developed over almost two decades by a researcher familiar with practical applications and mathematical modeling. Completely validated against exact solutions and physics-based checks through over a hundred documented examples, the self-contained model (with special built-in matrix solvers and iteration algorithms) with a -plain English graphical user interface- has been optimized to run extremely fast - seconds per run as opposed to minutes and hours - and then automatically presents all electric and magnetic field results through integrated three-dimensional color graphics. In addition to state-of-the-art algorithms, basic -utility programs- are also developed, such as simple dipole methods, Biot-Savart large diameter models, nonlinear phase and amplitude interpolation algorithms, and so on. Incredibly useful to oilfield practitioners, this volume is a must-have for serious professionals in the field, and all the algorithms have undergone a laborious validation process with real use in the field.

Spis treści

Preface xv

Acknowledgements xxi

1 Motivating Ideas General Formulation and Results 1

1.1 Overview 1

1.2 Introduction 2

1.3 Physical Model and Numerical Formulation 4

1.4 Validation Methodology 13

1.5 Practical Applications 16

1.6 Closing Remarks 34

1.7 References 35

2 Detailed Theory and Numerical Analysis 37

2.1 Overview 37

2.2 Introduction 40

2.3 Preliminary Mathematical Considerations 47

2.4 Boundary Value Problem Formulation 58

2.5 Computational Issues and Strategies 66

2.6 Typical Simulation Results 80

2.7 Post–Processing and Applications 112

2.8 Restrictions with Fast Multi–frequency Methods 126

2.9 Receiver Design Philosophy 128

2.10 Description of Output Files 131

2.11 Apparent Resistivity Using Classic Dipole Solution 138

2.12 Coordinate Conventions for Mud and Invasion Modeling 139

2.13 Generalized Fourier Integral for Transient Sounding 140

2.14 References 141

3 Validations Qualitative Benchmarks 142

3.1 Overview 142

3.2 Introductory Problems 148

3.3 Advanced Problems 245

3.4 Sign Conventions and Validation Methodology 277

3.5 References 279

4 Validations Quantitative Benchmarks at 0° and 90° 280

4.1 Overview 280

4.2 Wireline Validations in Homogeneous Media 281

4.3 Wireline Validations in Two–Layer Inhomogeneous Media 304

4.4 Electric and Magnetic Field Sensitive Volume Analysis for Resistivity and NMR Applications 328

4.5 MWD Steel Collar and Wireline Computations in Homogeneous and Nonuniform Layered Dipping Media 340

4.6 Exact Drill Collar Validation Using Shen Analytical Solution 347

4.7 Dipole Interpolation Formula Validation in Farfield 349

4.8 Magnetic Dipole Validation in Two–Layer Formation 352

4.9 References 355

5 Quantitative Benchmarks at Deviated Angles 356

5.1 Overview 356

5.2 Limit 1. No Collar, No Mud 356

5.3 Limit 2. Collar Only, No Mud 363

5.4 Limit 3. Mud Only, No Collar 371

5.5 Limit 4. Collar and Mud 377

6 Validations Quantitative Benchmarks at Deviated Angles with Borehole Mud and Eccentricity 382

6.1 Overview 382

6.2 Repeat Validations 382

6.3 References 439

7 Validations Receiver Voltage Response and Apparent Resistivity 440

7.1 Overview 440

7.2 Focused Studies 440

7.3 General Transmitter Design Philosophy 485

7.4 General Receiver Design Philosophy 487

7.5 Apparent Resistivity Estimation from Classic Dipole Model 490

8 Simulator Overview and Feature Summary 491

8.1 Overview 491

8.2 Simulator Comparisons 493

8.3 Technical Specifications 496

8.4 Advanced Logging Applications 498

8.5 Formulation Features 499

8.6 Computational Technology 503

8.7 User Interface 504

8.8 Integrated Utility Programs 505

8.9 Detailed Output and Integrated Graphics 506

8.10 System Requirements 507

8.11 Validation Approach 508

8.12 Simulator Speed Analysis 510

8.13 Sample User Interface Screens 511

8.14 Transmitter and Receiver Design Interface 517

9 Simulator Tutorials and Validation Problems 519

9.1 Problem Set 1. Dipole and Biot–Savart Model Consistency Validating Magnetic Fields 520

9.2 Problem Set 2. Validating Farfield Phase Predictions 528

9.3 Problem Set 3. Drill Collar Model Consistency Exact Drill Collar Validation Using Shen Analytical Solution 532

9.4 Problem Set 4. Magnetic Dipole in Two–Layer Formation 534

9.5 Problem Set 5. Effects of Eccentricity and Invasion 538

9.6 Problem Set 6. A Complicated Horizontal Well Geology 542

9.7 Problem Set 7. Effects of Layering, Anisotropy and Dip 546

9.8 Problem Set 8. Transmitter and Receiver Design 554

9.9 Problem Set 9. Apparent Anisotropic Resistivities for Electromagnetic Logging Tools in Horizontal Wells 560

9.10 Problem Set 10. Apparent Anisotropic Resistivities for Borehole Effects Invasion and Eccentricity 577

Cumulative References 583

Index 585

About the Author 591

O autorze

Wilson C. Chin, who earned his PhD from MIT and MSc from Caltech, heads StrataMagnetic Software, LLC in Houston, which develops mathematical modeling software for formation testing, MWD telemetry, borehole electromagnetics, well logging, reservoir engineering, and managed pressure drilling. He is the author of ten books, more than 100 papers, and over forty patents.

Blurb

Mathematically rigorous, computationally fast, and easy to use, this new approach to electromagnetic well logging gives the reservoir engineer a new dimension to MWD/LWD interpretation and tool design

Almost all publications on borehole electromagnetics deal with idealizations that are not acceptable physically. On the other hand, exact models are only available through detailed finite element or finite difference analysis, and more often than not, simply describe case studies for special applications. In either case, the models are not available for general use and the value of the publications is questionable.

This new approach provides a rigorous, fully three–dimensional solution to the general problem, developed over almost two decades by a researcher familiar with practical applications and mathematical modeling. Completely validated against exact solutions and physics–based checks through over a hundred documented examples, the self–contained model (with special built–in matrix solvers and iteration algorithms) with a plain English graphical user interface has been optimized to run extremely fast seconds per run as opposed to minutes and hours and then automatically presents all electric and magnetic field results through integrated three–dimensional color graphics.

In addition to state–of–the–art algorithms, basic utility programs are also developed, such as simple dipole methods, Biot–Savart large diameter models, nonlinear phase and amplitude interpolation algorithms, and so on. Incredibly useful to oilfield practitioners, this volume is a must–have for serious professionals in the field, and all the algorithms have undergone a laborious validation process with real use in the field.

This groundbreaking new volume contains:

• A general three–dimensional electromagnetic model for nondipolar transmitters in layered anisotropic media with dip, developed for MWD/LWD well logging and tool design, offering accurate solutions in seconds as opposed to minutes or hours
• An approach that helps readers explore new transmitter and receiver concepts and designs
• Information on model steel mandrels, charge radiation from layer interfaces, large coil and thin layer effects, anisotropic media and low resistivity pay, borehole eccentricity and invasion, with a new and powerful model developed from first principles
• A new approach that removes physical limitations associated with dipole, integral equation, Born, geometric factor or hybrid techniques and explains how these problems are overcome, building on advances from aerospace computational fluid mechanics
• Mathematical and programming details as well as ready–to–use software with integrated three–dimensional color graphics for those needing immediate answers