川西双鱼石构造反转的有限元模拟证据

川西双鱼石研究区位于龙门山构造带北段,近年双鱼石区块进行的油气勘探证明该区具有良好的油气资源条件,查明该区构造发育特征和构造演化历史对区内油气勘探和开发具有重要意义。本文通过野外地质调研和地震资料解释,认为双鱼石研究区具有构造正反转特征;通过有限元模拟分析,印证了双鱼石研究区构造演化经历了晚三叠世之前被动大陆边缘环境,发育高角度正断层,而后在燕山期和喜山期受到龙门山造山运动影响构造反转,早期高角度正断层上下相邻软弱层诱发逆断层。

Evidence from finite element modeling for structural reverse of Shuangyushi, northwestern Sichuan

The study area is located in the northern part of Longmenshan Belt, the oil and gas exploration in this area in recent years has proved that this area has good oil and gas resource conditions and the structural development characteristics and structural evolution history of this area is significant for oil and gas exploration and development. Field geological survey and seismic data interpretation indicate that change of fault from normal to reverse took place in this area. Finite element modeling verifies that the structural evolution of this area experienced the passive continental margin environment before the late Triassic, and developed high-angle normal faults. Then, the structure reversed under the influence of Longmenshan orogeny in the Yanshan and Himalayan movement periods, and reverse faults were produced in the adjacent weak layers above and below the early high-angle normal faults.