Basin Compartments and Seals
Basins worldwide exhibit an unexpected degree of hydrologic segregation. There can be regions of a sedimentary basin that are isolated from their surroundings by a relatively thin envelope of low-permeability rock with an interior of sufficiently high permeability to maintain a consistent internal hydrostatic fluid pressure gradient. These have been named pressure compartments. Presure compartments have several remarkable features, just one of which is that internal fluid pressures can greatly exceed or be significantly less than any regional topographically controlled hydrologic head or drain. This publication contains 30 chapters that take detailed looks at pressure compartments in general, and detail case studies of these compartments in specific basins, such as the Anadarko and Gulf of Mexico. The volume also looks at other considerations in sedimentary basins such as hydrodynamic and thermal characteristics, and mechanical properties of rock.
The Characteristics of Geopressure Profiles in the Gulf of Mexico Basin
Published:January 01, 1994
This paper is a summary of our work on the relationship between under-compacted shale and abnormal pressure in the Tertiary portion of the Gulf of Mexico Basin. A major objective of this study is to map the depth to the top of the undercompacted shale, as located using shale density (cuttings samples), conductivity, sonic, plus bulk density logs relative to the depth to the top of abnormal pore pressure as determined using bottom-hole pressure (BHP) and repeat formation tester (RFT) data. Geopressure profiles (formation pressure versus depth curves) were most useful for such mapping because the geopressure profiles showed...