Recent Advances in the Understanding of the Structure and Stratigraphy of West Luconia, Offshore Sarawak: Implications for Petroleum Systems and Prospectivity

Abstract

The West Luconia Province, offshore Sarawak, is a vast area covering in excess of 25,000 km². Bordered by the prolific Central Luconia Platform to the east and the Indonesian Natuna Sea to the west, the area is a largely under explored region with limited well penetrations and sparse legacy seismic coverage. Following initial exploration campaigns in 1970 and 1988, the area has seen limited exploration activity against an industry perception of the region containing limited volume, high risk opportunities. The structural history of the area is complex and the stratigraphy only partially understood from limited Well penetrations. The majority of Wells across The West Luconia Province have targeted obvious structures mapped on sparse 2D seismic data. These structures are not necessarily the optimum locations for targeting lower risk, sand rich play fairways. In addition, Wells in the south of The Province have largely been drilled on the footwalls of major half grabens i.e. in areas where reservoir may be poorly developed. The presence of thinned, condensed or eroded intervals on fault footwalls cause problems correlating away from these Wells as significant thicknesses of unpenetrated stratigraphy are predicted within the half graben fill. Recent seismic acquisition, coupled to reprocessing of legacy data has enabled a step shift in the understanding of The Province. Plays have been identified throughout the stratigraphy with stacked pay potential in many areas. In addition to significant overlooked potential in the more traditional and partially tested plays, play based exploration has highlighted significant previously overlooked potential. This includes the potential for sand prone deepwater systems in the north of The Province and deeply buried carbonate and clastic plays in the south. The deep prospectivity will require Wells to be drilled beyond 3,000 m BMSL with implications for overpressures and the possibility of challenging HPHT drilling but, with the potential for significant volumetric reward.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015