Identifying Reservoir Architecture in Mio-Pliocene Canyon Systems of the Northern Kutei Basin

Reader, Joanne; Vendrell-Roc, Jaume; White, Roger
Salamander Energy Plc, Singapore, Singapore.

Recent acquisition of 3D seismic data in the Bontang and SE Sangatta PSCs, Northern Kutei Basin by Salamander Energy Plc has enabled detailed mapping of Mio-Pliocene aged deepwater slope canyon and fan systems using seismic amplitude analysis and seismic facies mapping techniques. Gross canyon geomorphologies, dimensional data, internal depositional architectures and stacking patterns have been defined and documented and demonstrate the presence of significant sedimentary feeder systems on the paleoslope. Narrow linear upper slope canyons broaden and amalgamate into much larger canyons on the mid to lower slope areas. A wide variety of internal seismic facies architectures have been identified, from laterally continuous semi-confined sheet geometries through to channel-levee geometries. These architectures vary with position on the slope and through geological time and reflect the switching of sedimentary input areas on the shelf. Local syn-sedimentary tectonics including both extensional and compressional thrust faulting have in some areas modified depositional patterns, deflecting channel systems and causing significant sediment ponding in places. A high degree of vertical stacking of canyon systems against large scale inversion anticlines is common. These areas provide excellent drilling targets for exploration wells in the area. Gross canyon geometries and internal canyon seismic facies architectures have also been compared to the modern day seabed and published shallow seismic profiles in the Kutei Basin area and demonstrate that the present is indeed the key to the past for the Northern Kutei area. Comparison with other subsurface field analogues provides some additional comfort. This work has provided support for a new geological model for these exploration blocks in the far northern part of the Kutei basin which is distal from the modern day Mahakam Delta proven hydrocarbon province.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012