Abstract: Sequence stratigraphic study within an intraslope basin turbidite channel complex: Example from eastern offshore Nigeria

FABRE C., M. DALL'ASTA, D. CLAUDE, J.P. ROLANDO and F. PAUX

In eastern offshore Nigeria stacked turbidite channel complexes of the Kwa-Iboe (Lower Pliocene) Formation constitute a pure stratigraphic trap. The depositional setting for this turbidite system is within an intraslope basin. An integrated sequence stratigraphic study provided a precise image of the reservoir extent.

Seven appraisal wells and two recent seismic surveys were used: a 2DHR (125 X 125 meters) which had good vertical and horizontal definition of the channelized bodies, and a 3D (12.5 X 12.5 meters) which enabled more precise mapping of the body geometries. Four channelized intervals were mapped with the seismic.

Three major sedimentary sandprone reservoir facies were identified from core and well-log data: channels, channel-levees and lobe-type features. Channels often stack vertically or occur as isolated meandering forms within each channelized interval.

A detailed reservoir geometry model for each seismic interval was obtained through a calibration of the wells to the interval maps from the 2DHR seismic and the 3D attribute maps from the Sismage^TM workstation.

The gridded reservoir model incorporates the static geological model, built from seismic stratigraphy and sedimentology, which was the basis for a preliminary dynamic reservoir simulation. Geometry and petrophysics of the elementary sand bodies have been deduced from the well tests.

This integrated sequence stratigraphic study, from the definition of a geologic model to the reservoir simulation, enabled the number and the location of production and injection wells to be optimized.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria