The North Malay Basin: Analog for the Reservoir Distribution of the Triassic Rift Basins, Northeastern Thailand

Abstract

This reference is for an abstract only. A full paper was not submitted for this conference. Abstract The North Malay Basin is an intra-cratonic basin formed by rifting in early Tertiary time. North-South (N-S) and Northwest-Southeast (NW-SE) oriented normal faults form a series of asymmetric half grabens. Some of these have shown the best imaged seismically. Combined with a number of wells that penetrated the synrift section in this and adjacent half-grabens, leads us to a clear picture of the overall geometry and reservoir distribution of the basins. In attempt to understand more about the nature and type of reservoirs encountered in the North Malay Basin, Na Phor Song, the Triassic Rift Basin located in northeastern part of Thailand was selected to conduct geological field survey. The outcrop exposures of this basin and subsurface data from the North Malay Basin were studied and compared, resulting in the definition of 8 synrift sedimentary facies: Alluvial Facies, Fluvial Facies, Proximal Delta Facies, Shoreface Facies, Lacustrine Swamp Facies, Distal Delta Facies, Deep Lacustrine Facies and Fan Delta Facies. The same facies observed in the outcrops can be interpreted from well control and seismic sequence analysis in the half graben, North Malay Basin. The areal distribution of the seismic facies can provide important insights to understanding the overall geometry of the Triassic Rift Basins. The facies successions observed in outcrop in the Triassic Rift Basins provides the means to better understand and define synrift reservoir fairways in the North Maly Basin. The seismic and well facies evaluation conducted in the exploration program for the North Malay Basin can provide insights to better understanding the reservoir distribution in the Triassic Rift Basins. Together, they can provide the means to improve the prediction of reservoir and source-prone facies other rift basins in the Gulf of Thailand.