Seismic data analysis and Petrophysical Studies for Hydrocarbon Evaluation of "FEM" Field, Niger Delta, Nigeria

Abstract

A comprehensive 3D seismic interpretation and petrophysical analysis was performed on the 'FEM' Field in the Niger Delta. The objective was to integrate petrophysics and seismic data analysis for the assessment of the hydrocarbon potential of the field. Gamma-ray logs were used to delineate seven reservoirs, which were then correlated throughout the field to confirm the lateral continuity of these reservoirs. An in-depth petrophysical analysis of the 'FEM' well indicated that all the reservoirs contain oil and are all oil-down-to. The average petrophysical parameters of the reservoirs were estimated, revealing a porosity of 29%, water saturation of 27%, shale volume of 0.1, and a net-to-gross ratio of 0.034. The reservoirs delineated on the logs were transferred to the seismic record using the checkshot data from FEM- 3&4 wells and the synthetic seismograms. Six horizons were mapped across the entire study area, and time and depth maps were created to determine the structural architecture and the geometry of the reservoirs in the 'FEM' field. Two major faults were identified, trending in the NW-SE direction, with the structural traps located in the southeastern part forming a fault-assisted closure. All the wells were drilled targeting the crest of this closure. The Root Mean Square amplitudes generated for all the levels indicated the lateral extent of the reservoirs, but they did not conform to the structure and thus, are not direct indicators of hydrocarbons. The original oil in place in the 'FEM' field is estimated to be 2.35 billion barrels.