印尼宾都尼盆地侏罗系油气成藏特征及勘探潜力

宾都尼盆地是印尼东部重要的中生界含油气盆地之一,经历了克拉通内坳陷、裂谷期、被动陆缘和挤压反转期4期构造演化,形成现今弧后前陆盆地的构造格局。盆地的主要烃源岩和储盖组合多发育于中古生界,晚二叠世与早中侏罗世煤系地层是主力烃源岩,排烃高峰期始晚中新世,以生气为主。侏罗系三角洲-滨岸砂体为优质储层,原生粒间孔发育,平均孔隙度15%,平均渗透率18mD,属于中孔-中高渗透储层；盆地中北部前渊斜坡带发育一系列背斜、断背斜圈闭,且发现了大量气田群；天然气多以“下生上储”,即从前渊坳陷气源灶沿着砂体和断层运移至侏罗系砂岩圈闭聚集成藏。综合分析认为,储层质量和有效圈闭是侏罗系油气成藏的主控因素,东部逆冲褶皱带与海湾南部斜坡带是未来勘探的两个有利区带。

Exploration Potential and Characteristics of Hydrocarbon Accumulation of Jurassic in Bintuni Basin, Indonesia

The Bintuni basin is one of the most favorable oil and hydrocarbon-bearing basins in Indonesia. Base on many previous research achievements, drilling and seismic data, tectonic evolution and sedimentary filling are studied, especially focusing on hydrocarbon accumulation characteristics and exploration potential. Resutls show that Bintuni basin experiences rift, passive continental margin rift, passive margin and compress inversion four tectonic evolution stages and forms the structure framework of foreland basin. The main source rocks and reservoir-play are developed in the Mesozoic. The coal-bearing strata of late Permian and middle Jurassic are the major source rocks with large gas expulsion, and the primary time of hydrocarbon expulsion is at late Miocene. The sandstone of delta and onshore is the good reservoir with 200m thickness, 15% average porosity and 18mD average permeability. The gas field clusters are discovered in anticline and faulted anticline traps of foreland slope belt. The natural gas migrates into Juarrsic traps and accumulation along the thick and continuity sandstone and faults. Analysis shows the reservoir quality and effectiveness of traps are two factors controlling the accumulation in Bintuni basin. The eastern thrust belt and slope belt of Bintuni bay southern part have high potential and would be two favorable exploration areas.