APPLICATION OF WIRELINE LOGS IN SEQUENCE STRATIGRAPHIC ANALYSIS AND RESERVOIR CHARACTERIZATION OF ‘FOLA’ FIELD, OFFSHORE NIGER DELTA.

Abstract

Sequence stratigraphic analysis and reservoir characterization of “Fola” Field, offshore Niger Delta, Nigeria were carried out using wireline logs. This is with a view to determining the hydrocarbon potential of the field. A suite of composite logs from three wells within the Field such as the Gamma ray, resistivity, density and neutron were used. Lithologies were differentiated using Gamma ray logs while other petrophysical parameters –Net pay, net to gross, porosity, hydrocarbon saturation and volume of shale were determined using the Gamma ray, resistivity, neutron and density logs. Stratigraphic analysis of the field revealed eight stratigraphic surfaces. Lithofacies interpretation showed alternation of sand and shale within the Field. Interpretation of the stacking patterns revealed an alternation of Highstand Sytem Tracts (HST) and Trangressive System Tracts (TST) within sequences 1 to 6 and 8. There was presence of Lowstand System Tracts (LST) within the sequence 7. The sand – shale ratio varies from 3:2 and 2:1 within the sequences. Petrophysical properties of the field revealed that volume of shale ranges from 10% to 40%, porosity values are between 24% and 47%, hydrocarbon saturation ranges between 41 and 85 and the water saturation values also ranges between 15% and 59%. The results showed that the environment of deposition supports good potential for hydrocarbon.