南苏门达腊盆地油气地质特征与勘探潜力分析

摘要

以广泛收集的数据资料为依据，运用含油气盆地理论方法，总结南苏门达腊盆地构造沉积演化和油气地质特征，探讨油气分布规律，分析其勘探潜力。结果显示，南苏门达腊盆地是新生代弧后裂谷盆地，经历了裂前、裂谷、过渡、坳陷和反转等5个演化阶段。主力烃源岩为过渡期沉积的炭质页岩和煤层，储集层主要为上渐新统砂岩、下中新统灰岩和裂缝基底。油气总体呈现“深层气、中层油和气、浅层油”的分布特征，主要富集于构造及构造复合相关圈闭中。断裂、储层发育有利相带和凹中隆是控制油气分布的主要因素。盆地油气成藏条件良好，具有较好的勘探潜力。生烃灶周边断裂发育的斜坡、古隆起是有利的勘探区，凹陷内的岩性、地层圈闭也是有利的勘探目标，应加大对此类圈闭的研究和勘探力度。%Based on the data collected from various sources and applying the theories and methods of basin analysis,this paper summarizes the tectonic-sedimentation evolution and petroleum geology characteristics of South Sumatra Basin,discusses the oil and gas distribution patterns and analyzes its hydrocarbon exploration potential. The results show that the South Sumatra Basin is a Cenozoic back-arc rift basin,experiencing 5 stages in evolution, including pre-rifting,rifting,transition,sag and compression.The principal source rock of the basin is carbona-ceous shale and coal depositing during the transition stage.The main reservoirs are found in upper Oligocene sand-stones,lower Miocene carbonates and pre-Paleogene crack basement.Generally,the hydrocarbon distribution is characterized by patterns of gas in the deeper reservoirs,oil and gas in the middle reservoirs,and oil in the shallo-wer reservoirs.Oil and gas are enriched in the structural traps and structural combination traps.Faults,favorable sedimentary facies of reservoirs and paleo-highs are the principal factors controlling the oil and gas distribution.The South Sumatra Basin has good hydrocarbon accumulation conditions and favorable exploration potential.Faulted slopes surrounding the source kitchens,paleo-highs are the advantageous exploration areas.In addition,the strati-graphic traps and lithologic traps in the depressions are also prospecting exploration targets.They should be studied and explored deeply.