Publications

ConocoPhillips Indonesia is currently producing oil and gas from Kerisi and Hiu Fields, Block B, Natuna Sea. Kerisi and Hiu Fields are independent faulted four-way dip closures containing an oil leg overlain by a gas cap. Production is primarily from the Oligocene Gabus Massive sand. This study addresses a predictive technique to evaluate the upside potential from secondary reservoirs within the Gabus formation excluding the currently producing sands.Although the Kerisi and Hiu structures are relatively simple, the Gabus Formation was deposited in a stratigraphicaly complex fluvio-deltaic environment. The reservoir is generally high porosity and has a Class II to Class III AVA response that varies depending on reservoir properties and fluid type. Notably, lateral changes in gross sand thickness and net to gross of the package cause corresponding changes in the seismic response.The 3D seismic volume shows several other isolated bright events in the Gabus interval, outside of the primary producing reservoir, but with a similar AVA expression. Some of these have been penetrated by development wells which provide a means of calibrating their seismic expression to their reservoir properties.This work examines the non-unique AVA response of these anomalies and rather than making a deterministic prediction, uses Monte Carlo simulation to establish the thickness and net to gross ranges consistent with the anomaly. These reservoir properties can further be used to determine the viability of future drilling and completion targets to optimize field production.