Gunung Kembang carbonate reservoir is a challenging field, with its low recovery factor, very thin oil column, but large gas cap and moderate aquifer support. Gunung Kembang carbonate facies and sequence have been identified from core description and from well correlation from the latest in-house study. Transgression and regression occurred during the carbonate depositional process, reflecting in the facies described from core. Some facies groups which have certain biota assemblages provide a good production performance, while others perform badly. The ability to determine good or poor facies is critical for deciding on the next drilling plan, since our best facies is about 20 feet thick. To know the amount of recoverable oil is essential for optimal exploitation of this field. Seismic inversion is one method to extract additional information from conventional seismic data. Inversion can increase the resolution of conventional seismic data and reservoir characterization at a different level. It results in optimized volumetric, improved ranking of leads/prospects, better delineation of drainage areas and identification of the ‘sweet spot’ in field development studies. Such an approach reduces uncertainties and drilling risks and is an important aspect for optimizing an exploration and hydrocarbon development strategy. Observation of the acoustic and elastic impedance value (P-S Impedance and Lambda-Mu-Rho) of well data in carbonate reservoirs strongly indicates hydrocarbon anomaly in the reservoir. Statistical analysis of well data performed prior to inversion allows an evaluation of the relationship between impedance, porosity and Lambda-Mu-Rho analysis, along with their potential for predicting the best new well location in the development field.
Author : Y. Yanto, T. Febriwan