Comparative Studies of Ekenkpon Shale Subsurface Distribution in the Calabar Flank

Abstract

The Ekenkpon Shale is one of the Cretaceous sequences of the Calabar Flank with the structural and subsurface facies studied in terms of their distribution and lateral. Materials used in this research are processed seismic and well log data from Wells A, B and C drilled within the study area. The procedure adopted was to compare the structural and stratigraphic analysis of previous and current research carried out in the study area. Well log data were viewed matched with processed seismic data. Composite stratigraphic section generated showed correlatable the Ekenkpon Shale facies, their lateral extents and subsurface distribution. Wells A and B drilled 0.8km apart in south-central Calabar Flank and well C drilled 4.7km from well B encountered Ekenkpon Shale. Comparison of the subsurface facie distribution of Ekenkpon Shale, in Wells A, B and C showed identified facies correlated across the studied wells whereas correlations modified after Nyong, Reijers and Petters, showed that only Well B penetrated the Ekenkpon Shale which pinched out before getting to Well C NE and SW of the Calabar Flank. Analysis of works by Nyong, Reijers and Petters when compared with the current study modified the subsurface distribution of the Ekenkpon Shale. The stratigraphy established in this study showed a continuous sequence of Ekenkpon Shale from the SW to the NE of the Calabar Flank compared with the surface Ekenkpon Shale as observed at different outcrop locations by the works of Nyong, Reijers and Petters is not extensive.