Abnormal Pressures in Hydrocarbon Environments


Book Description

The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin.




Abnormal Pressures While Drilling


Book Description




Studies in Abnormal Pressures


Book Description

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.




Origin and Prediction of Abnormal Formation Pressures


Book Description

Knowledge of the presence of abnormally-high pressure zones (AHFP) prior to drilling into them can prevent considerable economic losses and, possibly, save human lives. The various origins (undercompaction, tectonics, etc.) of AHFPs are discussed, followed by the description of predictive techniques in clastic, carbonate and salt-bearing formations. In addition to the well-logging predictive techniques, the authors discuss smectite-illite transformation and the chemistry of interstitial solutions. Other topics covered include (a) abnormally low formation pressures and subsidence, and (b) mathematical modelling. Loss of potential production may result if AHFPs are not properly identified and evaluated. Many hydrocarbon-bearing formations with AHFPs are erroneously "condemned".This book is of interest to engineers and geologists involved in the (a) evaluation, (b) drilling in, (c) completing, and (d) producing from hydrocarbon reservoirs with AHFPs.




Abnormal Formation Pressures


Book Description

Abnormal Formation Pressures




Sediment Compaction and Applications in Petroleum Geoscience


Book Description

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.




Reservoir Engineering


Book Description

This book provides a clear and basic understanding of the concept of reservoir engineering to professionals and students in the oil and gas industry. The content contains detailed explanations of key theoretic and mathematical concepts and provides readers with the logical ability to approach the various challenges encountered in daily reservoir/field operations for effective reservoir management. Chapters are fully illustrated and contain numerous calculations involving the estimation of hydrocarbon volume in-place, current and abandonment reserves, aquifer models and properties for a particular reservoir/field, the type of energy in the system and evaluation of the strength of the aquifer if present. The book is written in oil field units with detailed solved examples and exercises to enhance practical application. It is useful as a professional reference and for students who are taking applied and advanced reservoir engineering courses in reservoir simulation, enhanced oil recovery and well test analysis.




Impact of Natural Hazards on Oil and Gas Extraction


Book Description

Since the dissolution of the Soviet Union almost a decade ago, there has been rapid evolution of interactions between the Western nations and individual countries of the former Soviet Union. As part of that interaction, the autonomous independent Republic of Azerbaijan through its scientific arm, the Geological Institute of the Azerbaijan Academy of Sciences under the Directorship of Academician Akif Ali-Zadeh and Deputy Director Ibrahim Guliev, arranged for personnel to be seconded to the University of South Carolina. The idea here was to see to what extent a quantitative understanding could be achieved of the evolution of the Azerbaijan part of the South Caspian Basin from dynamical, thermal and hydrocarbon perspectives. The Azeris brought with them copious amounts of data collected over decades which, together with the quantitative numerical codes available at USC, enabled a concerted effort to be put forward, culminating in two large books (Evolution of the South Caspian Basin: Geological Risks and Probable Hazards, 675 pps; and The South Caspian Basin: Stratigraphy, Geochemistry, and Risk Analysis, of which were published by the Azerbaijan Academy of 472 pps. ) both Sciences, and also many scientific papers. Thus, over the last four to five years an integrated comprehensive start has been made to understand the hydrocarbon proneness of the South Caspian Basin. In the course of the endeavor to understand the basinal evolution, it became clear that a variety of natural hazards occur in the Basin.







Quantitative Analysis of Geopressure for Geoscientists and Engineers


Book Description

Geopressure, or pore pressure in subsurface rock formations impacts hydrocarbon resource estimation, drilling, and drilling safety in operations. This book provides a comprehensive overview of geopressure analysis bringing together rock physics, seismic technology, quantitative basin modeling and geomechanics. It provides a fundamental physical and geological basis for understanding geopressure by explaining the coupled mechanical and thermal processes. It also brings together state-of-the-art tools and technologies for analysis and detection of geopressure, along with the associated uncertainty. Prediction and detection of shallow geohazards and gas hydrates is also discussed and field examples are used to illustrate how models can be practically applied. With supplementary MATLABĀ® codes and exercises available online, this is an ideal resource for students, researchers and industry professionals in geoscience and petroleum engineering looking to understand and analyse subsurface formation pressure.