The strike-slip and thrust composite structure characteristics and oil-gas exploration direction in North-West margin of Yitong Graben
Tang Da-qing1,2, Chen Hong-han1,2, He Sheng1,2, Zhang Hui3
1. Education Ministry Key Lab of Tectonics and Petroleum Resources, China University of Geosciences, Wuhan City,Hubei Province,430074,China;
2. Petroleum Dept., School of Resources, China University of Geosciences, Wuhan City, Hubei Province, 430074, China;
3. Exploration & Production Research Institute,Jilin Oilfield Company Ltd.of PetroChina,Songyuan City,Jilin Province, 138000, China
Abstract：The geological conditions of the surface and subsurface in North-West margin of Yitong Basin are very complicated, its low exploration degree and poor seismic data quality have a severe impacts on the recognition of the subsurface structure characteristics and oilgas exploration activities in this region. By using new structure analysis method in this paper and based on integrated studies on new outcrops, drilling data, seismic data and other data, it is found that since Neogene the North-West margin of Yitong Basin has mainly shown strike-slip and thrust composite structure characteristics with thrust as main trend and dextral strike-slip as secondary trend, as a result a 2-4 Km wide fault-fold structural belt has been formed and its evolution has been controlled by reversion tectonic activity in the region. The belt has favorite conditions for hydrocarbon accumulation, it may be the new prospect area for oil exploration in this region, it is believed that the en-echelon anticline belt, the en-echelon fault blocks and the downwall of the thrust fault which were formed by strike-slip and thrust function should be the targets for the future exploration in Yitong Basin.
