Geophysics Under Stress

Provides an overview of the sensitivity of elastic waves in the earth to in situ stress, pore pressure, and the anisotropy of the rock fabric. A variety of applications and real data examples is presented, with particular emphasis placed on the rock-physics basis underlying the use of geophysical data for solving geomechanical problems.

Provides an overview of the sensitivity of elastic waves in the earth to in situ stress, pore pressure, and the anisotropy of the rock fabric resulting from the depositional and stress history of the rock and introduces several of the applications of that sensitivity. A variety of applications and real data examples is presented, and particular emphasis is placed on the rock-physics basis underlying the use of geophysical data for solving geomechanical problems. The book, which accompanies the 2010 SEG/EAGE Distinguished Instructor Short Course, provides the basis for applying geophysics and rock-physics solutions to geomechanical challenges in exploration, drilling, and production and is aimed at a broad range of geoscientists and engineers who work in the petroleum industry. The integrated nature of the material makes the book suitable for individuals from all subsurface disciplines, including geophysics, geomechanics, rock physics, petrophysics, geology, and geomodeling as well as drilling engineering, reservoir engineering, and petroleum engineering.

Rock Dynamics and Geophysical Exploration: Introduction to Stress Waves in Rocks deals with a theoretical tool for predicting stress waves in rocks. The book considers both elastic and Kelvin type materials, and also explains some experiments of stress waves in rocks. The book reviews concepts in the analysis of stresses and deformations, the fundamental equations used to examine the propagation of stress waves in certain types of solids, and the characteristics features of plane waves in elastic mediums. The text explains wave propagation in rocks due to a detonating charge (resulting in stress waves with a spherical symmetry), the response of a cylinder to an outside excitation (resulting in a cylindrical wave), or a harmonically oscillating stress from an outside excitation (resulting in a harmonic input pulse). The text explains Kelvin materials as a generalization of the behavior of the material where a damping effect is incorporated with the elastic medium being studied. The book also compares experimental results of the application of stress waves in rocks with theory, and explains the sensitivity criteria for tunnels. The text cites as an example, the significance of the interaction between tunnels and shock waves before any tunnel expansion can be made by engineers. The book will prove valuable for geologists or for structural, civil, and mining engineers.

Stress Field of the Earth’s Crust is based on lecture notes prepared for a course offered to graduate students in the Earth sciences and engineering at University of Potsdam. In my opinion, it will undoubtedly also become a standard reference book on the desk of most scientists working with rocks, such as geophysicists, structural geologists, rock mechanics experts, as well as geotechnical and petroleum en- neers. That is because this book is concerned with what is probably the most pe- liar characteristic of rock – its initial stress condition. Rock is always under a natural state of stress, primarily a result of the gravitational and tectonic forces to which it is subjected. Crustal stresses can vary regionally and locally and can reach in places considerable magnitudes, leading to natural or man-made mechanical failure. P- existing stress distinguishes rock from most other materials and is at the core of the discipline of “Rock Mechanics”, which has been developed over the last century. Knowledge of rock stress is fundamental to understanding faulting mechanisms and earthquake triggering, to designing stable underground caverns and prod- tive oil fields, and to improving mining methods and geothermal energy extraction, among others. Several books have been written on the subject, but none has atte- ted to be as all-encompassing as the one by Zang and Stephansson.

This interdisciplinary book encompasses the fields of rock mechanics, structural geology and petroleum engineering to address a wide range of geomechanical problems that arise during the exploitation of oil and gas reservoirs. It considers key practical issues such as prediction of pore pressure, estimation of hydrocarbon column heights and fault seal potential, determination of optimally stable well trajectories, casing set points and mud weights, changes in reservoir performance during depletion, and production-induced faulting and subsidence. The book establishes the basic principles involved before introducing practical measurement and experimental techniques to improve recovery and reduce exploitation costs. It illustrates their successful application through case studies taken from oil and gas fields around the world. This book is a practical reference for geoscientists and engineers in the petroleum and geothermal industries, and for research scientists interested in stress measurements and their application to problems of faulting and fluid flow in the crust.

High-Pressure Research: Applications in Geophysics contains the papers presented during a U.S.-Japan joint seminar held in Honolulu, Hawaii, 6-9 July 1976. The seminar brought together scientists engaged in high pressure-high temperature research to exchange ideas on the latest state-of-the-art developments, their experimental results, and their latest interpretations with regard to the significance of these results to the geophysical sciences in general. Four formal sessions were held. Of the forty-two papers presented at the seminar, thirty-nine appear as contributed papers and three as abstracts in this volume. The papers in Session I examine the geophysics and geochemistry of the crust and upper mantle. The contributions in Session II focus on phase transitions related to Earth's deep interior. Session III is devoted equations of state and shock wave experiments while Session IV covers instrumentation, pressure calibration, and standardization.