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 10: Abnormally High Formation
Pressure and Seal Impacts on Hydrocarbon Accumulations in the Nile Delta and North Sinai
Basins, Egypt, by M. Nashaat,
Pages 161 - 180
Chapter 10
Abnormally High Formation Pressure and Seal Impacts on Hydrocarbon
Accumulations in the Nile Delta and North Sinai Basins, Egypt
M. Nashaat
Egyptian General Petroleum Corporation, Cairo, Egypt
Abstract
The Nile Delta and North Sinai Basins are active geodynamic (high subsidence rate)
basins with a thick, clay-dominated Oligocene to Recent sedimentary section. Abnormally
high formation pressures have developed in this section and in the underlying pre-Tertiary
section primarily due to rapid sedimentation. Secondary mechanisms may be locally
superimposed where the Messinian evaporite super seal is present. The abrupt development
of pore pressure in the southern part of the Nile Delta is believed to be due to changes
in the volume of pore fluids or rock matrix as a consequence of either aquathermal
expansion, hydrocarbon generation, or thermal cracking of oil to gas in the lower
Miocene-upper Oligocene compartment. Fluid flow in the Nile Delta and North Sinai Basins
is mainly due to compaction-and thermal-driven forces.