PREDICTION OF FAVORABLE ZONE FOR FRACTURE DEVELOPMENT OF SHALE GAS RESERVOIR IN JIAOSHIBA AREA BY USING ELASTIC-PLASTIC INCREMENT METHOD

摘要

Shale gas is an unconventional natural gas resource with immense potential in twenty-first Century, which can be an important supplement to conventional energy sources and can effectively relieve the pressure on the world's energy. Wufeng- Longmaxi formation developed a suit of black shale rich in shale gas which were in Jiaoshiba area located in the Sichuan basin with a vast developing prospective. In the process of shale gas development, the development of natural fractures is related to the production of shale gas. To improve the efficiency of shale gas exploitation, Elastic-Plastic Increment Method (EPIM) is used to predict the fracture development of shale gas reservoir by simulating the modern tectonic stress field. The results show that the distribution and characteristics of the present stress field in the area are similar, and each unit is slightly different. The direction of present stress field varies from about SEE118° to SEE 130°; The characteristics of present tectonic stress field contour maps reveal that, on the plane, the favorable area for fracture development is mainly concentrated in the northeast and southwest, and the direction of fracture distribution is similar to the fault trend, and is distributed in a zonal pattern; in the vertical direction, the area of the favorable area for fracture development is larger, and with the deepening of the depth, the more the cracks in the central part are not developed.