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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 63 (1979)

Issue: 3. (March)

First Page: 546

Last Page: 546

Title: Grondin Oil Field, Gabon: ABSTRACT

Author(s): J. P. Vidal

Article Type: Meeting abstract


After deposition of thick Aptian salt while the Atlantic Ocean was opening, the Gabon sedimentary basin was filled with mainly sandy continental and littoral deposits on the eastern margin and marine deposits on the west. The marine formations are mainly shaly, but a few sand layers, some thick, may be intercalated. Grondin oil field is related to one of these sands--the Batanga sandstone of Maestrichtian age. The sandstones are generally clean with good porosity, but some shales are interbedded. Gross thickness may reach more than 150 m.

The trap is an anticlinal salt structure, without noticeable piercing, though a median fault is obvious at the top. The producing sandstone is reduced by an internal unconformity. Nevertheless, the oil field, with a small gas cap, consists of a unique pool with a unique oil-water contact. Source rocks are post-salt marine shales, particularly in the Turonian. Migration probably occurred during the Miocene.

Grondin oil field, situated 40 km offshore, was discovered in 1971 by Elf Gabon and was rapidly developed. The initial recoverable reserves are estimated at 30 million tons (approximately 200 million bbl).

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Copyright 1997 American Association of Petroleum Geologists