Integrating Wells and 3D Seismic Data to Delineate the Sandstone Reservoir Distribution of the Talang Akar Formation, South Sumatra Basin, Indonesia
Widodo, Robet W.
San Diego State University, Purworejo, Indonesia.
This study describes the distribution and depositional environment of selected sandstone reservoirs in the Oligocene-Miocene fluvial-deltaic Talang Akar Formation (TAF), Delta (DLT) area , Jambi Sub-Basin, South Sumatra Basin. Three-Dimension (3D) seismic data covering an area of 170 km2 and well logs from four wells are used.
The area lies in an early Tertiary rift basin that was subjected to Plio-Pleistocene compression. Growth strata along extensional faults demonstrate that the TAF was deposited during active rifting and basin growth. Well logs (gamma ray and mud logs) show interbedded sandstone, shale and coal typical of a fluvial-deltaic and shallow marine setting. Based on the well logs, the sandstone layers are interpreted as mainly distributary channel fill facies.
Two productive horizons defined by drill stem tests at two wells are mapped throughout the seismic volume, together with major faults and top basement. These two horizons are examined using amplitude maps. The amplitude maps are related to the character of the interface between the sandstone and the adjacent layers. They may also be affected by tuning effects.
Strong variations from amplitude maps from both horizons are visible appearing deltaic depositional features and are interpreted to be distributary channel and mouthbar clustering. Those clustering were controlled by northeast-southwest faults that were formed and active at Oligocene-Miocene. New prospects can be recommended based on those intensive delineated facies sands with very careful thought about tuning effect.
AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012