(1) University of Buea, Buea, SW Province, Cameroon
(2) SHELL P.D.C, Port Harcourt, Rivers State, Nigeria
The search for oil has over recent years witnessed a shift in emphasis from structural to stratigraphic traps. Most often, such stratigraphic traps exhibit very subtle expressions and are difficult to find. The Anambra Basin in S.E. Nigeria has experienced a very low success rate of drilled wells. This Cretaceous basin has not received enough attention from explorationists because it has always appeared to be a more difficult and less rewarding province than the Niger Delta. However, with exploration moving out into the deeper and more risky offshore areas of the delta, prospects earlier regarded as poor in the Anambra Basin are beginning to look more attractive than they did a few years ago.
In this study, an attempt to unravel possible hideouts of the basin’s hydrocarbons has been done by supplying stratigraphic information through the analysis of interval velocities along seismic lines in an essentially inverse modeling technique: the Differential Interformational Velocity Analysis method.
Plots of Differential Interformational Velocity Analysis generated from overlays of Dix-derived interval velocities for various horizons and intervals (formations) have been employed to narrow down the stratigraphic search for hydrocarbons to specific low-velocity anomaly zones along seismic lines passing through various prospects within the basin. The analysis has also diagnosed the Mamu and Nkporo formation as most lucrative targets for stratigraphically trapped hydrocarbons.
AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana