Page 6 - Applied Petroleum Geomechanics

Foreword

In the past, projects involving “rock engineering” were designed using
classical continuum mechanics “closed-form” solutions. By presenting such
solutions in terms of dimensionless parameters, the consequences of their
variations from the initial assumptions provided the engineer with valuable
practical insights. Such an approach is still used in most cases where only
limited pertinent laboratory and/or field data are known.
In the last quarter century, rock mechanics/geomechanics has become
increasingly concerning with energy-related issues, mainly, the extraction
of hydrocarbons and, more recently, a renewal interest in hot-dry rock
geothermal reservoirs. Practical examples can be found in the US Pro-
ceedings published yearly by ARMA in which the number of papers
somewhat reflects the health of a particular discipline. An often main
remaining issue is that rock formations have been subject, over geological
times, to complex, ill-defined, and often unknown histories of loading and
deformations; hence, variability and heterogeneity are inherent features of
most locations. In addition, as deeper horizons and more complex geom-
etries are contemplated, unusual stress and temperature conditions are
encountered, combined with the presence of natural deformable fractures
have led to the development of more sophisticated numerical approaches.
In unconventional petroleum resources, combining horizontal drilling
technology with multiple parallel stimulations by hydraulic fractures has
recently resulted in unexpected substantial recoverable reserves. This
contributed to the United States recently becoming a net exporter of
hydrocarbons.
As technologies advance in the energy industries, geomechanics finds
more applications and has become an important knowledge to guide
exploration and production activities. For me, Dr. Jincai Zhang’s book
offers the advantage of first assembling some basic concepts an engineer
could be confronted with and require a rapid solution owing to time
constraints. This book provides and facilitates such approaches by
combining theoretical fundamentals with practical examples. Another
valuable information contained in this book is the shared data provided via
detailed examples of worked-out solutions. Wherever possible, the author
has been willing to share empirical relationships, derived from vast
worldwide experience.

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