Bua Ban North Field: Extending the Miocene Play Into the Western Gulf of Thailand

Ripple, Robert; Mitchell, James; Cox, Dan; Moon, Jerry; Roever, Robert; Htein, Nyan; Rubio, Scott; Peace, Geoff; Laird, Andrew; The, Ronald; Pringle, John
Coastal Energy, Houston, TX.

The Bua Ban North Field is a Lower Miocene oil discovery in the Songkhla Basin, a tilted half-graben basin in the western Gulf of Thailand. The field was discovered in 2011; to date, the drilling of 22 wells in the field has resulted in a 2P (proven plus probable) STOOIP volume of 204 MMBO with recoverable reserves of 67MMBO. The field is a faulted four-way closure with a central keystone graben overlying a deeper inversion feature. The faulted domal feature in the overlying Lower Miocene section provides the trap for the Lower Miocene reservoirs. The Lower Miocene are fluvio-deltaic sands deposited in a fresh-water lacustrine setting. Lower Oligocene lacustrine shale constitutes the Type I source rock and high heat flow has resulted in expulsion of a 36 API waxy crude. After initially focusing exploration efforts on the Paleogene section, the chance discovery of a 6 m pay zone in the Lower Miocene shifted focus, resulting in the discovery of the Bua Ban North Field. Average field-wide pay thickness and porosity are 20 m and 26%, respectively from seven distinct stratigraphic intervals at depths ranging from 900 to 1600 m. First production was achieved four months following discovery and is expected to exceed 25000 BOPD by end 2012. Horizontal wells and early water injection are being utilized to maximize recovery, which is expected to reach 30%. Success at Bua Ban North has resulted in extension of the Lower Miocene oil play in the western Gulf of Thailand. Shallow reservoir depths and efficient engineering practices have resulted in an economic success at a field which can be expected to reach giant classification after full development.

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