Integrating Seismic Data with Well Logs in Structural and Stratigraphic Mapping: A Case Study of Emi Field Offshore Niger Delta, Nigeria

A. P. Aizebeokhai and A. I. Olayinka
University of Ibadan, Ibadan, Nigeria

The subsurface geometry, stratigraphy and hydrocarbon trapping potential of Emi field, offshore Niger Delta were investigated by integrating 3D seismic data with well logs to delineate possible prospect areas in the field. Lithologic units were identified on the logs and consequently correlated. Stratigraphic cross-sections were drawn through wells 4, 1 and 3, and through wells 4 and 5. The result shows that the shale and sand units are laterally continuous, though pinch-outs/wedge-outs are evident. Lithofacies were tied to the seismic data. The high-amplitude and continuous reflection events were found to correspond to sand units whereas low-amplitude reflection events correspond to shale units. Relatively low amplitude reflection events may represent shaly sands or sandy shales. Few cases of misties attributed to soft shales, excessive filtering of the seismic data, uncertainties in the time-depth relations, broken-up reflectors and faults were observed. Four horizons, H1, H2, H3 and H4, were mapped and structural contour maps were produced for each of the horizons. Faults were picked on the seismic sections and posted to the maps produced. Closures, regarded as good hydrocarbon prospect areas, were delineated in the structural contour maps. The horizons mapped are laterally continuous !n both the stratigraphic cross-sections drawn and the seismic records. Thus, location of new hydrocarbon habitat can easily be predicted. Test drilling can be carried out in he prospect areas delineated. To effectively explore the study area and optimized wells location it is essential to integrate all existing exploration and evaluation tools.