川西坳陷须家河组气藏与古构造关系

基于川西坳陷须家河组"超深、超压、超致密、超晚期构造"的地质条件,通过中坝、合兴场及平落坝3个已知气藏的生烃史、孔隙演化史、构造演化史等方面的系统分析,从勘探成功与失利两个方面进行分析,明确了古构造在气藏成藏过程中的奠基作用。燕山期古隆起带决定了气藏的展布;早期成藏具有普遍性;古构造-成岩圈闭是区内重要的含油气圈闭类型。川西坳陷须家河组气藏经历了早期常规圈闭、中期冻结、晚期改造等多个演化阶段。马井-德阳地区存在燕山期隆起,且具有相似的演化过程,应是一个前景良好的区带。

Relationship between palaeostructure and gas reservoirs in Xujiahe Formation in western Sichuan depression

According to the geologic conditions of Xujiahe Formation in western Sichuan depression to be characterized by super-deep, overpressure, super-tight and super-late structures, systematic analysis of hydrocarbon generation history, pore evolution history and structural evolution history of the known Zhongba, Hexingchang and Pingluoba gas reservoirs and analysis of both positive and negative exploration cases have been made.It has been clear that palaeostructures have acted as the basis of gas accumulation. Yanshanian palaeohigh zone determined the distribution of gas reservoirs, characterized by common early reservoiring, and palaeostructural-diagenetic traps to be the main types of hydrocarbon traps in the study area. Gas reservoirs in Xujiahe Fm in western Sichuan depression have experienced several evolution stages, including conventional trapping in the early stage, suspension in middle period and reconstruction in late stage. Majing-Deyang area, where there is Yanshanian palaeohigh, has experienced similar evolution process, thus it might be a prospective play.