中苏门答腊盆地新生代沉积演化及其油气意义

Cenozoic Sedimentary Evolution in the Central Sumatra Basin and Its Hydrocarbon Significance

构造演化控制了中苏门答腊盆地始新世—全新世的海侵—海退旋回:始新世—渐新世,盆地处于同生裂谷早期,盆地低洼区主要发育小范围陆相沉积;中新世时,盆地进入同生裂谷后期而继续断裂扩张,早期发生了来自西南方向的海侵,中中新世之后盆地几乎全部被海水淹没;到中新世晚期盆地开始遭受挤压,海水逐渐退出盆地。生储盖分布明显受沉积相控制,烃源岩和盖层主要为深海—半深海页岩,而储层主要发育于三角洲相和滨浅海砂岩中。

Tectonic evolution controlls transgression-regression cycle of the Central Sumatra Basin in Eocene-Holocene.During Eocene-Oligocene,the basin is at the stage of Early Syn-rift Unit and mainly deposits a small range of continental sedimentary.Basin enters the stage of Late Syn-rift Unit in Miocene and continued to expand,the basin which occurrs transgression from southwest in the early of miocene is almost submerged by sea water after middle Miocene.To the late Miocene,the Central Sumatra Basin are crushed and sea water gradually withdraws from basin.Distribution of the genetic,reservoir and seal layer are controlled by sedimentary facies,source rocks and cap rocks are mainly bathyal-abyssal facies shales,and reservoirs are developed in the sandstone of delta facies and littoral-shallow marine sediments.