This book discusses how sediments compact with depth and applications of the compaction trends. Porosity reduction in sediment conveniently indicates the degree of sediments compacted after deposition. Published empirical curves- the compaction curves- are depth-wise porosity variation through which change in pore spaces from sediment surface to deeper depths e.g. up to 6 km can be delineated. Porosity is derived from well logs. Compaction curves, referred to as the Normal Porosity Profile of shales, sandstones and shale bearing sandstones of different models are reviewed along with the different mechanical and chemical compaction processes. These compaction models reveals how porosity reduces depth-wise and the probable reason for anomalous zones. Deviation from these normal compaction trends may indicate abnormal pressure scenarios: either over- or under pressure. We highlight global examples of abnormal pressure scenarios along with the different primary- and secondary mechanisms. Well logs and cores being the direct measurements of porosity, well log is the only cost-effective way to determine porosity of subsurface rocks. Certain well logs can detect overpressure and the preference of one log above the other helps reduce the uncertainty. Apart from delineation of under-compacted zones by comparing the modeled- with the actual compaction, porosity data can also estimate erosion.

The objectives of this book are: (1) to educate the prospective Pressure Evaluation Geologist to a basic level of expertise; (2) to provide a reference tool for the experienced geologist; and (3) to foster constructuve thought and continued development of the field geologist. Despite the incorporation of many new ideas and concepts, elaboration of the more re cent concepts is limited due to space considerations. It is hoped that the geologist will follow up via the literature referenced at the end of each chapter. Easy reference is provided by the detailed table of contents and index. A glossary of terms, definitions, and formulae adds to the usefulness of this reference text. ACKNOWLEDGMENTS FOR FIGURES Figure 2-7 is reprinted by permission of the AAPG from Barker, 1972. Figure 4-21 is courtesy of Totco Figure 5-2 is reprinted by permission of the Oil and GasJournal from Matthews and Kelly, 1967. Figure 5-4 is reprinted by permission of the SPE-AIME from the Journal of Petroleum Technology from Eaton, © 1969. Figure 5-5 is reprinted by permission of the SPE-AIME from Hubbert and Willis, © 1957.

When Fertl's first book, Abnormal Formation Pressures, was published by Elsevier in 1976, the topic was relatively new in book form. In the years that followed, his book became the standard work for petroleum engineers and drillers. The list of major petroleum provinces with abnormally high pore pressures has grown steadily over the years, and with it has grown our knowledge and experience. There have also been technological advances. A new book was required, but no longer could the topic be covered adequately by one person. The problems of abnormally high formation pressures encountered in the subsurface while drilling for petroleum are very diverse, involving geologists, geophysicists, reservoir engineers, drilling engineers, and borehole logging engineers. The acute anticipation of such pressures before drilling has become possible with modern technology. This book treats these developments and covers the following topics: world occurrences, the geology of abnormal pore pressures and the background theory, reservoir engineering aspects of abnormally pressured reservoirs, detection of abnormal pressures by geophysical methods before drilling and during drilling, and their evaluation after drilling. It examines the special problems of shallow hazards from shallow abnormal pressures, and relief-well engineering to control blowouts. It also examines the generation of abnormal pressures from hydrocarbon generation in the Rocky Mountains, and the distribution of abnormal pressures in south Louisiana, USA. The topics are examined from a practical point of view with a theoretical background. There is a glossary of terms, and a relevant practical conversion table. Both SI units and the conventional US oil industry units are used.

Abnormal Formation Pressures

Applied Petroleum Geomechanics provides a bridge between theory and practice as a daily use reference that contains direct industry applications. Going beyond the basic fundamentals of rock properties, this guide covers critical field and lab tests, along with interpretations from actual drilling operations and worldwide case studies, including abnormal formation pressures from many major petroleum basins. Rounding out with borehole stability solutions and the geomechanics surrounding hydraulic fracturing and unconventional reservoirs, this comprehensive resource gives petroleum engineers a much-needed guide on how to tackle today's advanced oil and gas operations. - Presents methods in formation evaluation and the most recent advancements in the area, including tools, techniques and success stories - Bridges the gap between theory of rock mechanics and practical oil and gas applications - Helps readers understand pore pressure calculations and predictions that are critical to shale and hydraulic activity