RESERVOIR FORMATION REGULARITY AND FAVORABLE AREA PREDICTION OF MALAY BASIN

The source rocks of Malay Basin include lacustrine shale and fluvial delta coal and shale, in which the lacustrine source rocks are dominated, and the shale of K Formation has the best hydrocarbon generation potential. The source rocks in central basin are usually over-mature, while those at the edge are mostly in oil generation window or immature. The tectonic inversion of Malay Basin occurred in Middle-Late Miocene, which was mainly concentrated in the southeastern and central basin and closely related with hydrocarbon accumulation. The inversion in the center is more intensive than that in the flank of basin and increases southeastward. The basin is roughly divided into basement, bottom, middle and upper reservoir combinations. The Late Oligocene-Middle Miocene structural reservoir combination is the most significant one, with the oil reserves accounting for 85% and natural gas 48% of the basin. The source rocks experienced the process of multi-phase hydrocarbon generation and mixed hydrocarbon generation, and the hydrocarbon generation in the south of basin was restrained. The oil-gas migration is mainly lateral, supplemented by vertical migration. The distribution of oil-gas reservoir is mainly controlled by source rock maturity and basin shape, which is presented as oil reservoir in the southeast and center and gas reservoir in the north. The Malay Basin is divided into 6 exploration areas, among which the southeastern extruded anticline is the main oil-gas production area with the oil reserves making up 69% and natural gas reserves 62% of the entire basin. Nine target areas are proposed, including 3 potential favorable exploration areas and 6 new exploration areas.