Amplitude Study For The Direct Hydrocarbon Detection In The Seismic Interpretation Of The Ofemini Prospect In The Eastern Niger Delta

Abstract

A total of two wells were drilled in Ofemini field. Ofemini-2 well has resistivity, gamma ray, sonic and density logs as displayed alongside with the synthetic seismogram. The aim of the study is to interpret seismic sections for structures and possible hydrocarbon prospects. The data used for the study include seismic data, petrophysical logs and sandsfile. The log data covers the interpreted level (E8.0).
The objective horizon (E8.0) shows fairly good sand development. Eleven 3-D seismic lines were used for the study. The average spacing for each shot point is 25m. The structural interpretation suggests that structural closure exists in the horizon mapped. The conformity of the amplitude anomaly supports that it is a direct hydrocarbon indicator. The amplitude study indicates high amplitudes on the structure and low amplitudes off the structure. The high amplitude is related to hydrocarbon while the low amplitude suggests brine saturants. The occurrence of strong amplitude reflection (amplitude anomaly) is as a result of low acoustic impedance of the hydrocarbon filled sand. This is indicative of gas accumulation and is evidenced by the well data


Keywords: Seismic, Interpretation, Amplitude, Anomaly, Indicator.

Global Journal of Geological Sciences Vol. 6 (1) 2008: pp. 75-93