Turbidite Reservoirs from Total West Africa Acreage

Martine Bez¹, Patrice Imbert¹, Rigobert Mougamba², and Francois Temple^1
1Total, Pau, France
²Total Gabon, Port Gentil, Gabon

A series of cores will be displayed to illustrate the variety of turbidite systems producing in Total’s Gulf of Guinea acreage. Each example is accompanied by a summary on the depositional context, highlighting the regional geology, the seismic and log character, and reservoir correlations. The cores on display will be supplemented by 1:1 scale high-resolution photographs to show full sections, reservoir and non-reservoir.

The cores have been selected to show various types of turbidite reservoirs. The Tertiary of the Lower Congo basin provides good examples of both channel-levee complexes and lobe complexes, each with its characteristic facies association, log character and correlation style. In addition to reservoirs, the same series also show non-reservoir facies, either developed as internal seals in the series, or as intra-reservoir heterogeneity. There are also a number of post-depositional effects, sand injection in particular, that play an important role in enhancing vertical reservoir communication.

A totally different style of turbidites will be illustrated by a core from the Anguille field in the upper Cretaceous of Gabon. The reservoirs have now been producing for over 40 years, but their depositional system is far less well understood than the Tertiary of Angola, in part because of a much lesser seismic visibility. The system is non-channelized, reservoir orientation is dominantly along the slope, but correlations from well to well are very difficult in detail.

AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery