Publications

The XY field is a marginal oil field in the western part of the Central Sumatra Basin (CSB) and is covered by 3D seismic. The XY field started production in 2012. The oil originates from the Lower Sihapas sandstone reservoir, similar to other oil fields in the CSB. The Lower Sihapas sandstone as the primary reservoir in the XY field has overall gross thickness reaching up to 58 ft. Routine Core Analysis (RCAL) and Special Core Analysis (SCAL) are available from reservoir core interval in one of the wells. The reservoir consists of very fine to fine, well sorted sandstone, some pyrite, glauconitic and calcareous with thin layer of claystone and siltstone. The low and relatively high resistivity characteristics of the oil and water bearing zone respectively in the XY field becomes a unique challenge that partly causes an overestimation of the reserves. Prudent and detailed analyses for petrophysics and modeling in the XY field has been undertaken to re-evaluate and minimize errors. This paper will address some of the issues and causes related to low resistivity found in the main pay zone in the XY field as input for a strategic concept of finding and evaluating other exploration candidates surrounding the area.