伊朗库姆盆地油气成藏机理分析

库姆盆地是以前寒武系变质岩为基底的中新生代盆地,通过对中下侏罗统舍姆沙克组和渐新统—中新统库姆组两套烃源岩的有机质丰度、类型、成熟度及油源对比等地球化学分析表明,舍姆沙克组烃源岩为一套有效的烃源岩层系,库姆组为一套潜在的烃源岩层系。舍姆沙克组烃源岩在早白垩世开始进入生烃门限,大约在17Ma时进入湿气和凝析油阶段,上新世早期盆地的快速沉降使侏罗系源岩达到过成熟阶段。经对库姆盆地成藏要素的演化过程进行分析,认为库姆盆地的区域石油地质背景有利于油气藏的形成、演化。库姆盆地既存在以舍姆沙克组(及库姆组)为源岩的新近系油气藏,也可存在舍姆沙克组原生油气藏。燕山期和喜山期形成的圈闭是本区的有利勘探目标。 

A PRELIMINARY STUDY ON PETROLEUM ACCUMULATION IN THE QOM BASIN,IRAN

The Qom Basin was developed in Mesozoic and Cenozic on the Precambrian metamorphic base. The analytic results of organic abundance, organic type, hydrocarbon-generating evolution of source rock and oil-source correlations indicated that Shemshak Formation (Jurassic) are effective source rocks. And Qom Formation (Oligocend-Miocene) are potential sources rocks. For the Shemshak Formation, organic matters entered into oil window in the Early Cretaceous, and were evolved into wet gas and condensate zone in about 17 Ma. At the Early Pliocene (about 5 Ma),the rapid subsidence of Qom Basin brought on the over maturation of Shemshak Formation. Study of accumulation conditions showed that Qom Basin was in favor of the formation and development of petroleum system. In Qom Basin, there might be hydrocarbon accumulations with traps formed in Neogene and sourced from Shemshak Formation (and Qom Formation), there also might be accumulations with reservoir rocks and source rocks both were Shemshak Formation.