Petroleum geology of rift basins in Niger, Chad, and Central African Republic

Conference · Thu Aug 01 04:00:00 EDT 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5848624

Genik, G J ^[1]

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1. Exxon Co. International, Houston, TX (United States)

Ten Cretaceous-Tertiary rift basins in Niger, Chad and the Central African Republic (C.A.R.) are defined and the petroleum geology is overviewed based on proprietary exploration results derived from more than one million km{sup 2} of aeromagnetics, 10,520 line-km of gravity profiles, 49,721 km of reflection seismic, and 50 exploration wells. The data were acquired by Exxon with partners Shell, Chevron, Elf, Conoco, Texaco, and Amax Oil Gas During 1969-1989. In Niger and Chad, the West African rift subsystem includes the extensional basins of Termit, Tefidet, Tenere, Grein/Kafra, N'Djel Edji, and Bongor. These rift basins contain up to 15,000 m of Cretaceous to Cenozoic continental and marine clastics. Key exploration elements are Tertiary and Cretaceous fluvial to tidal sandstone reservoirs, Tertiary and Cretaceous marine to lacustrine shale source rocks and seals, with traps in normal fault blocks and anticlinal closures. There have been six oil discoveries in the Termit basin. In C.A.R., the Central African rift subsystem incorporates the extensional Doba and transtensional Doseo and Salamat basins flanking the Borogop dextral wrench fault. These basins contain up to 7,500 m of chiefly Cretaceous continental clastics. key exploration elements are Lower and Upper Cretaceous fluvial to lacustrine sandstone reservoirs, Lower Cretaceous lacustrine shale source rocks, lacustrine to flood-plain shale and mudstone seals, with traps in mainly faulted anticlinal closures. There have been six oil discoveries in the Doba basin and three in the Doseo basin. The studied petroleum geology in the rifts of Niger, Chad, and C.A.R. indicates that potentially commercial volumes of oil remain to be discovered.

• OSTI ID: 5848624
• Report Number(s): CONF-910978--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:8
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
AFRICA
CENOZOIC ERA
CENTRAL AFRICAN REPUBLIC
CHAD
CRETACEOUS PERIOD
DEVELOPING COUNTRIES
EXPLORATION
EXPLORATORY WELLS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGIC TRAPS
GEOLOGY
GEOPHYSICAL SURVEYS
GRAVITY SURVEYS
MAGNETIC SURVEYS
MESOZOIC ERA
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NIGER
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
RESERVOIR ROCK
RESOURCES
RIFT ZONES
SEDIMENTARY BASINS
SEISMIC SURVEYS
SOURCE ROCKS
SURVEYS
TERTIARY PERIOD
WELLS