Play Analysis and Exploration Potential of the Rakhine Basin, West Myanmar
Xu, Zhi-cheng; Lv, Fuliang; Fan, Guozhang; Hui, Sun
PetroChina Hangzhou Research Institute of Geology, Hangzhou, China.
The Rakhine basin, which is located in the western coastal province of Myanmar and covers an area of 165,000sq.km., is still a frontier basin although there has been a spurt of exploration activity following the giant Shwe gas discovery in 2003. In our research, more than 8500 km of recent 2D seismic data and 1100 sq.km. 3D seismic data as well as some log data in the Rakhine basin were studied to analyze and evaluate play and exploration potential of the basin.
Play potential of the basin is limited to the major seismic sequences of the Upper Eocene, Miocene and Pliocene. In the onshore and coastal areas of the basin, the Upper Eocene and Miocene structural plays are predominant because of strong tectonic deformation. The Upper Eocene and Miocene deltaic sandstones comprise the reservoirs for the small and shallow accumulations, and interbedded shales provide top seals. Traps mainly include anticlines, faulted anticlines and fault blocks that are associated with folding and thrusting.
However, in the offshore and deepwater areas of the basin, the Pliocene stratigraphic- structural play is predominant because of relatively weak tectonic deformation. The Pliocene submarine fan sandstones comprise the most promising reservoirs of the basin (including Shwe gas field), and hemipelagic shales provide excellent intra-formational seals. Stratigraphic- structural traps and stratigraphic traps represent the main traps types.
Knowledge on the potential source rocks in the basin is relatively limited. Oligocene -Lower Miocene marine shales are considered to be the most important source rocks. Generation and expulsion possibly began in the Late Pliocene. Hydrocarbon migration is believed to occur through faults and passage beds.
The investigation indicates that the Rakhine Basin bears exploration potential based on a basic prospectivity assessment. In the onshore and coastal areas, the Upper Eocene and Miocene structural plays remain under-explored at depth. And in the offshore and deepwater areas, there are a large number of Pliocene submarine channel complexes and depositional lobes that remain to be explored.
AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012