INTEGRATION OF SEQUENCE STRATIGRAPHY AND COHERENCE ATTRTE FOR REEROR COECTT AA ‘ARE’ FIELD ONSHORE NIGER DELTA.

Abstract

A combine use of biofacies, well log, check shot and seismic data were analysed and interpreted for reservoir connectivity analysis. Using the biofacies data, the abundant and minimum microfauna were used to delineate maximum flooding surface (MFS) and sequence boundary (SB), respectively. Environment of deposition surfaces viz channel, lower shoreface and upper shoreface were delineated from the well log curve. The biofacies analysed result and well log data were processed and four reservoirs were delineated across wells from west to east direction using the petrel software. The results of well log analysis were tied to seismic data (seismic to well tie) using check shot data for horizon and fault mapping. Using coherence attribute analysis, the mapped fault were enhanced to determine the size, thickness and geometry of the faults. The modelled faults result were used to determine the impact of the faults on shale gouge ratio (SGR), fault permeability and reservoir connectivity. Based on the above analyses, thirteen faults (F1 to F13) comprising of three major (F1, F3 and F7), six (6) antithetic faults ( F2, F4, F5, F9, F10, F11) and four (4) synthetic faults (F6, F8, F12, F13) were delineated on the structural map, characterized with sizes ranging from 100 m to 1200 m. Furthermore, the influence of the faults on SGR, fault permeability established 15 % to 70 % and 0.5 mD to 100 mD respectively. The SGR results implies poor to good fault sealing capacity of the reservoirs; while that of permeability suggest fair to good reservoir connectivity. The study findings can be employed to enhance the hydrocarbon productivity in the field.