川东南焦石坝地区寒武系天然气成藏条件

Hydrocarbon accumulation conditions of Cambrian natural gas at Jiaoshiba structure in the southeast of sichuan basin

针对四川盆地东南部野外露头与钻井资料综合分析,通过地球化学分析、储层评价研究、盆地模拟及构造平衡分析等技术,对川东南焦石坝地区寒武系烃源岩、储层、盖层保存和构造演化等油气成藏条件展开研究。川东南焦石坝地区寒武系具有良好的烃源岩条件;发育龙王庙组和洗象池群两套有利储层,储集空间主要为溶孔和溶洞;发育下寒武统和下志留统两套区域性泥质盖层以及中上寒武统膏盐岩盖层,良好的生储盖空间配置利于油气成藏。焦石坝构造形成于印支期,燕山-喜山时期最终定型,有利于油气早期聚集。

The hydrocarbon accumulation conditions such as source rocks,reservoir,caprocks and tectonic evolution at Jiaoshibaarea,Southeast of Sichuan basin are analyzed based on the comprehensive analysis of outcrops and drilling data by means of geochemicaland reservoir evaluation methods,basin modeling and balanced geological section technology. The results show that there are favorablesource rocks and two sets of fine reservoirs in the Longwangmiao and Xixiangchi formation,of which the major reservoir space is composedof dissolved caves and pores;the regional cap of gypsum-salt in the Middle-Upper Cambrian and shale in Lower Cambrian and LowerSilurian Series have good space configuration of source rocks,which provides favorable accumulation conditions for oil and gas. The Jiaoshibastructure is formed in Indosinian and set in Yanshan-Himalayan stage,which is favorable for hydrocarbon accumulation in early stage.