Chapter from:
AAPG Memoir 70: Abnormal Pressures in Hydrocarbon Environments
Edited by B.E. Law, G.F. Ulmishek, and V.I. Slavin
Copyright ©1998 by The American Association of Petroleum Geologists. All rights
reserved.
Memoir 70, Chapter 11: Causes of Formation and
Distribution of Abnormally High Formation Pressure in Petroleum Basins of Ukraine, by A.J. Polutranko, Pages 181 - 194
Chapter 11
Causes of Formation and Distribution of Abnormally
High Formation Pressure in Petroleum Basins of Ukraine
A.J. Polutranko
UkrDGRI, Lviv, Ukraine
Abstract
The maintenance of abnormally high formation pressure (AHFP) over long periods of
geologic time cannot be explained by compaction or structural deformation without the
addition of fluids from underlying rocks. Abnormally high pressures develop in the deepest
parts of basins that contain 8-10 km of sedimentary rocks. The deeper part of the
sedimentary fill typically occurs in the zones of late catagenesis and incipient
metamorphism with temperatures ranging from 200 degrees to 300 degrees C. The observed increase of
formation pressure above normal hydrostatic pressure with increasing depth and
temperature, in conjunction with other factors, indicates that extended zones of AHFP
first appear at temperatures of 175 degrees C and higher. At lower temperatures, abnormally high
pressures occur only locally at the crests of anticlinal structures.
