"The Geological Interpretation of Well Logs"

SYNOPSIS

As in the previous editions, the new, 3rd edition describes each of the common well logging tools in terms of physical principles, basic tool design, log characteristics, quantitative and then qualitative, mainly geological uses. Petrophysics, that is, the use of logs for quantifying hydrocarbons is also considered, but only briefly. Following the chapters on individual tools, the information that all the logs provide is drawn together in chapters on lithology, facies, sequence analysis and sequence stratigraphy, in which geological applications are the main subject. All the chapters are illustrated by real log examples.

The 3rd edition contains much new material which reflects the changes that have occurred since the second edition was published. Included for the first time are Logging While Drilling (LWD) tools for all the conventional measurements, Modular Formation Testers and Nuclear Magnetic Resonance (NMR) tools. There is also a much expanded chapter on the modern image logs, both wireline and LWD. A full contents list is shown below.

One more change. The third edition is in full colour throughout, as demanded by the modern log set and modern presentations.

WHO SHOULD USE THE BOOK

Judging from the past, the book is helpful to those who are just beginning to acquaint themselves with logs, in either industry or academia, to those who are not involved with logs all the time and want a book on logs as an occasional reference (such as sedimentologists, micropalaeontologists and geophysicists) and to active rig geologists.

‘The Geological Interpretation of Well Logs’ has been used in the past as a course manual, both by industry and by academia. The present layout has been influenced by the fact that both authors have given courses themselves, around the world (www.nautilusworld.com), besides actively using logs as tools in their daily work.

3rd EDITION: FULL CONTENTS LIST

CHAPTER 1 INTRODUCTION
1.1   Well logs – a definition and some history
1.2   Well logs – the necessity
1.3   Wireline logs – the making
1.4   LWD logs – the making (MWD and definitions)
1.5   Log runs
1.6   Log grid presentations
1.7   Digital log data formats
1.8   Log acronyms (mnemonics)
1.9   The logging companies
1.10   Well log interpretation and uses
1.11   This book – content and aims

CHAPTER 2 THE LOGGING ENVIRONMENT
2.1   Introduction
2.2   Invasion and the pressure environment of boreholes
2.3   Temperature environment of boreholes
2.4   Damage around the borehole
2.5   Logging tool capabilities: beds
2.6   Logging tool capabilities: spatial considerations
2.7   Depth measurement in boreholes
2.8   Logging tool conveyancing methods
2.9   Conclusion

CHAPTER 3 SUBSURFACE PRESSURE MEASUREMENT
3.1   Introduction
3.2   Subsurface fluid pressures
3.3   Subsurface Pressure Tools
3.4   Sampling
3.5   Comment

CHAPTER 4 TEMPERATURE LOGGING
4.1   Generalities
4.2   Subsurface temperatures and geothermal gradients
4.3   Borehole temperature measurement
4.4   True formation temperatures and borehole corrections
4.5   Temperature log uses

CHAPTER 5 CALIPER LOGS
5.1   Generalities
5.2   Caliper tools
5.3   Log presentations
5.4   Simple, two-arm, wireline caliper interpretation
5.5   Four-arm calliper interpretation

CHAPTER 6 SELF POTENTIAL OR SP LOGS
6.1   Generalities
6.2   Principles of measurement
6.3   The SP tool
6.4   Log characteristics
6.5   Quantitative uses
6.6   Qualitative uses

CHAPTER 7 RESISTIVITY LOGS
7.1   Generalities
7.2   Theoretical considerations
7.3   Zones of invasion: resistivity variations
7.4   Resistivity tools
7.5   The different types of resistivity tools
7.6   Modern resistivity tools: some examples
7.7   Log characteristics
7.8   Quantitative uses of the resistivity logs
7.9   Qualitative uses

CHAPTER 8 THE GAMMA RAY AND SPECTRAL GAMMA RAY
8.1   Generalities
8.2   Natural gamma radiation
8.3   Tools (Table 8.3)
8.4   Log characteristics
8.5   Geochemical behavior of potassium, thorium and uranium and natural radioactivity
8.6   Radioactivity of shales and clays
8.7   Quantitative use of the simple gamma ray
8.8   Qualitative use of the simple gamma ray
8.9   Quantitative use of the spectral gamma ray
8.10   Qualitative and semi-quantitative uses of the spectral gamma ray log

CHAPTER 9 SONIC OR ACOUSTIC LOGS
9.1   Generalities
9.2   Older, compressional wave, wireline sonic tools (pre-1985)
9.3   Full waveform array, dipole, wireline sonic tools
9.4   LWD sonic tools
9.5   Porosity determination from the sonic log
9.6   Qualitative and semi-quantitative uses of sonic logs (non-seismic)
9.7   Quantitative uses of sonic logs (non-seismic)
9.8   Seismic applications of sonic logs

CHAPTER 10 THE DENSITY AND PHOTOELECTRIC FACTOR LOGS
10.1   The density log, generalities
10.2   Principles of measurement
10.3   Tools
10.4   Log characteristics
10.5   Quantitative uses
10.6   Qualitative uses
THE PHOTOELECTRIC FACTOR LOG (or Litho-Density)
10.7   Generalities
10.8   Principles of measurement
10.9   Log characteristics
10.10   Quantitative uses
10.11   Qualitative uses

CHAPTER 11 THE NEUTRON LOG
11.1   Generalities
11.2   Principles of neutron measurement
11.3   Tools
11.4   Log characteristics
11.5   Quantitative uses
11.6   Qualitative uses
11.7   Neutron-density combination: lithology identification
11.8   Gamma-neutron tools

CHAPTER 12 LITHOLOGY RECONSTRUCTION FROM LOGS
12.1   Introduction
12.2   Subsurface lithology
12.3   Lithology from drill data – the mud log
12.4   Lithology from cores – direct physical sampling
12.5   Manual lithology interpretation from logs (qualitative)
12.6   Computer aids to manual lithology interpretation (semi-quantitative)
12.7   Software derived lithology from logs (quantitative)
12.8   Conclusion

CHAPTER 13 NMR
13.1   Generalities
13.2   Principles of measurement
13.3   Tools
13.4   Log characteristics
13.5   Petrophysical uses
13.6   Geological uses

CHAPTER 14 DIPMETER
14.1   Generalities
14.2   Dipmeter tools
14.2   Dipmeter processing
14.4   Processed log presentations
14.5   Dipmeter quality assessment
14.6   Dipmeter interpretation: the basics
14.7   Sedimentary dipmeter interpretation
14.8   Structural dipmeter interpretation
14.9   Conclusions

CHAPTER 15 IMAGE LOGS
15.1   Generalities
15.2   Wireline imaging tools
15.3   LWD imaging tools
15.4   Image processing: electric and acoustic
15.5   Some basic practicalities for interpretation
15.6   Sedimentary interpretation of images, some concepts and examples
15.7   Structural interpretation of images, some examples
15.8   Quantitative uses of electrical imagesimages: thin beds, permeability, fractures and facies
15.9   What next?

CHAPTER 16 FACIES, SEQUENCES AND DEPSOITIONAL ENVIRONMENTS FROM LOGS
16.1   Introduction
16.2   Facies
16.3   Log-based sequence (electrosequence) analysis: a tool for sedimentological and stratigraphic interpretation
16.4   Carbonate sediments
16.5   Conclusions

CHAPTER 17 SEQUENCE STRATIGRAPHY AND STRATIGRAPHY
17.1   Introduction
17.2   High resolution siliciclastic sequence stratigraphy using well logs
17.3   Log examples of sequence stratigraphic surfaces
17.4   Sequence stratigraphy: the building blocks
17.5   Carbonate sequence stratigraphy
17.6   Lithostratigraphy
17.7   Correlation methods
17.8   Conclusions

CHAPTER 18 CONCLUSIONS

REFERENCES

INDEX