Simulation studies of a horizontal well producing from a thin oil-rim reservoir in the SSB1 field, Malaysia

Abstract

Three-dimensional simulation studies have been carried out to investigate the performance of a horizontal well producing from a thin oil-rim reservoir, X3/X4 in the SSBI field, Malaysia. A heterogeneous model was used which honored the reservoir heterogeneity as deduced from logs. Simulation results indicate that gas and water cresting are inevitable even at low oil production rate of 100 STB/D because of the thin oil column of only 45 feet. Continued production under the current gas/oil ratio limit of 1500 SCF/STB results in an oil recovery at 15 years production of 6% OOIP, compared to 7% OOIP if the gas/oil ratio limit is increased to 10,000 SCF/STB, with negligible oil resaturation losses into the gascap. Simulation results indicate that oil recovery from the X3/X4 reservoir would be increased if wells are produced at gas/oil ratios higher than 1500 SCF/STB, and the horizontal wells are completed at, or as near as possible to, the oil-water contact.