Well logging lies at the intersection of applied geophysics, petroleum and geotechnical engineering. It has its roots in the tentative electrical measurements in well bores which were made by the Schlumberger brothers some 80 years ago in the earliest days of systematic petroleum exploration. Today, a variety of specialized instruments is used to obtain measurements from the borehole during, as well as after, the drilling process. This readable and authoritative treatment of the physics of these measurements dispels the "black magic" of well log interpretation by relating them, including those obtained by the latest generation of tools, to rock physics. It offers a thorough exposé of the physical basis of borehole geophysical measurements, as well as an introduction to practical petrophysics -- extracting desired properties from well log measurements.

Two decades ago, the first edition of this book demystified the process of well log analysis for students, researchers and practitioners. Since then, the industry has changed enormously: technical staffs have been slashed, and hydrocarbons have become increasingly harder to locate, quantify, and produce. In addition, new techniques of drilling have engendered a whole new family of measurement devices incorporated into the drilling string. Petroleum deposits are becoming scarce, while demand steadily increases. Massive corporate restructuring and the "graying" of the workforce have caused the technical competence involved in the search and exploitation of petroleum to become scarce. In this comprehensive update, the authors include all of the new logging measurement technology developed in the last twenty years and expand the petrophysical applications of the measurements. In sum, this is a thoroughly revised graduate level textbook, as well as a useful handbook for any practicing earth scientist.

Erratum.- An Overview of Well Logging.- to Well Log Interpretation: Finding the Hydrocarbon.- Basic Resistivity and Spontaneous Potential.- Empiricism: The Cornerstone of Interpretation.- Resistivity: Electrode Devices and How They Evolved.- Other Electrode and Toroid Devices.- Resistivity: Induction Devices.- Multi-Array and Triaxial Induction Devices.- Propagation Measurements.- Basic Nuclear Physics for Logging Applications: Gamma Rays.- Gamma Ray Devices.- Gamma Ray Scattering and Absorption Measurements.- Basic Neutron Physics for Logging Applications.- Neutron Porosity Devices.- Pulsed Neutron Devices and Spectroscopy.- Nuclear Magnetic Logging.- to Acoustic Logging.- Acoustic Waves in Porous Rocks and Boreholes.- Acoustic Logging Methods.- High Angle and Horizontal Wells.- Clay Quantification.- Lithology and Porosity Estimation.- Saturation and Permeability Estimation.