Numerical Modeling of 3D Tectonic Stress Field for the Xujiaweizi Fault Depression of Songliao Basin
SANG Guangseng1,2,XIA Bin1,3,ZHANG Shengli1,CAI Zhourong3,LIANG Zhengzhong1,2 and WAN Zhifeng1,2(1.Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,Guangdong,China; 2.Graduate University of Chinese Academy of Sciences,Beijing 100049,China; 3.School of Marine Science,Sun Yat-Sen University,Guangzhou 510275,Guangdong,China)
The Xujiaweizi fault depression in the Songliao basin is rich in hydrocarbon and is one of the important target areas. The deep formations in the Xujiaweizi fault depression was studied comprehensively through the finite element method,and the stress field of the deep structures was simulated. The result shows that a sinistral stress field may result in pinching action. The Maxim Coulomb shear stress is significantly larger than that of neighboring areas which small faults would be induced easily. In the deep part of the Xujiaweizi fault depression,pinching action is obvious in the Xuxi slope zone,Fengle uplift and Songzhan swell. Compressional movement may not occurred during the sedimentation of the Yingcheng Formation,the compressional structures can also be formed under the tensional environment.