Detailed seal analysis, Lower Cretaceous rocks of the North Sinai basin, Egypt: Effects on hydrocarbon migration and accumulation in overpressured regimes

Conference · Fri Mar 01 00:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7079205

Nashaat, M ^[1]

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1. Egyptian General Petroleum Corp., Cairo (Egypt)

The filling mechanism of petroleum traps in the North Sinai basin has been studied, taking into account the area's maturation history, the hydrodynamic parameters, and the seal efficiencies. The purpose of this study was to ascertain whether or not sizeable accumulations of hydrocarbons could be expected and to investigate the origin of the oil discovered to date. Formation pressure regimes in the North Sinai basin include highly overpressured reservoirs with undercompacted shale, starting at relatively shallow depths. In particular, the deeper closed hydraulic systems usually exhibit abnormally pressured regimes in individual fluid compartments. The pressure regimes are separated from each other by seals that are of particular interest to explorationists, as they frequently support oil and gas pools. The fracture pressures as well as the formation pore pressures were used together in some wells to evaluate seal quality. This detailed seal analysis has identified many regional seals and pressure compartments and their lateral and areal extent. These seals seem to control the hydrodynamic regime in the underlying permeable Lower Cretaceous reservoirs, and along with source maturation strongly affect the migration of hydrocarbons from source rocks and their accumulation in reservoirs. The water chemistry of the undercompacted sediments and overpressured reservoirs agrees with the different hydrodynamic systems mapped. Water chemistry zones clearly define different hydraulic systems. Originally, they are the freshwater aquifer of Lower Cretaceous overlain by higher salinity formations.

• OSTI ID: 7079205
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
EGYPTIAN ARAB REPUBLIC
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
NATURAL GAS
ENVIRONMENTAL TRANSPORT
GEOLOGIC TRAPS
PETROLEUM
CRETACEOUS PERIOD
GEOLOGIC HISTORY
GEOPRESSURED SYSTEMS
PETROLEUM GEOLOGY
PORE PRESSURE
RESERVOIR PRESSURE
SEDIMENTARY BASINS
AFRICA
DEVELOPING COUNTRIES
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
MASS TRANSFER
MESOZOIC ERA
MIDDLE EAST
MINERAL RESOURCES
RESOURCES
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration