The Petroleum Geology of the Tanintharyi Basin, Offshore Myanmar: Implications for Reservoir Potential in Lacustrine Delta Systems

Booth, John E.; Evans, Huw
Exploration, Twinza Oil Limited, Bangkok, Thailand.

The Tanintharyi Basin is located in shallow, near coastal waters at the northern end of the Mergui Archipelago. It is north-south elongated half-graben some 80 km in length and 20 km in width, with the basin bounding fault on its western side. Although definitive age dating of the deepest fill has yet to be obtained, it is thought that rifting was initiated in the early Late Oligocene and subsidence continued into the Pleistocene, when it ceased following an episode of basin inversion.

The basin is covered with an extensive grid of 2D seismic lines and there have been three exploration wells drilled : Zagawa-1 (Texaco 1992-3, oil discovery) and Kinmon-1 (Texaco 1995, dry hole) and Zagawa-2 (Twinza 2010, oil discovery).

The basin contains up to 4,000 m of sediment, with lacustrine source rocks distributed throughout, providing a large potential hydrocarbon charge, and numerous prospective closures based on fault and fold traps have been mapped using the 2D seismic data. However, although sandstones are common, they have proved to be poor reservoirs due to a large amount of interstitial clay and have flowed on test.

The Tanintharyi Basin is unique in SE Asia as its fill is predominantly lacustrine from initiation in the Oligocene right through to the Pleistocene. This talk will discuss the controls of the structural architecture of the basin and the configuration of lacustrine delta systems on the deposition of reservoirs and source rocks in the Tanintharyi Basin.

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