Development characteristics of fault accommodation zone and its significances of petroleum geology in Gaoyou depression

Key words:  Gaoyou depression  fault accommodation zone  Zhenwu fault system  Wubao fault system  significances of petroleum geology

Abstract:

The fault accommodation zone is a significant geologic structure which regulates the kinematic equilibrium in tec-tonically deformed regions，so the geologic distribution characteristics of the main faults and significances of petroleum geology of various tectonic belts in Gaoyou depression were investigated on the basis of comprehensive analysis of geology and seismic. The results show that there are four big fault accommodation zones in Gaoyou depression, namely Zhenwu-Wubao fault synthetic-overlapping fault accommodation zone, Zhen ② inside fault synthetic-overlapping fault accommodation zone, Wu (J) inside fault gynthetic-collinear fault accommodation zone, and Hanliu-Wu ② fault antithetic-coliinear fault accommodation zone. The synthetic fault accommodation zones are apt to form water systems. Various sedimentary fans and structural traps are developed, and are close to the oil-generating center, 80 they are places of main oilfields in Gaoyou depression. While antithetic fault accommodation zones, being uplifts of low amplitude, are not favorable to oil-gas pooling because of no development of water systems and the sand bodies, and long distance from oil-generating centers.