THE APPLICATION 3D SEISMIC DATA INTERPRETATION TO HYDROCARBON PROSPECT MAPPING IN “DEDE”FIELD,NIGER DELTA

Abstract

In certain frontiers, the dense sampling of 3D seismic surveys can help to identify subtle subsurface structures and thin beds through detailed imaging. The 3D technology can also provide a hint on reservoir quality. This research was carried out to show how 3D seismic data interpretation is applied to robust subsurface imaging and prediction of lateral reservoir quality. The integrated study involved 3D visualization, direct reservoir identification, structural interpretation, amplitude extraction and seismic reservoir evaluation constrained by porosity at the wells. Initial 3D visualization was done by scanning through seismic lines to locate seismic amplitude anomalies that can be related to direct hydrocarbon indicators. Amplitudes of interpreted horizons were tracked to access stratigraphic features. The tie between the significant seismic reflections and borehole section were established from the synthetic seismogram. Well log analysis was done and results compared with seismic interpretation. The seismic interpretation confirmed reservoirs which have appeared on well logs. In addition, a bright spot was observed on some of the lines in areas not penetrated by wells. Trapping mechanism for the bright spot may be stratigraphic. In addition, structural maps revealed four way closures as traps for the reservoirs interpreted from well logs at the center of the field. Implications of these results in determining reservoir characteristics of sandstones and in permitting hydrocarbon production from well log analysis is further discussed