Control of coupling among three major factors for formation of high-efficiency gas reservoir——A case study on the oolitic beach gas reservoir in Feixianguan Formation in the northeast Sichuan Basin

作     者：WANG ZeCheng1, ZHAO WenZhi2, ZHANG ShuiChang3, WANG HongJun1 & YU Qian4 1 Institute of Geology, Research Institute of Petroleum Exploration and Development, Beijing 100083, China 2 Research Institute of Petroleum Exploration and Development, Beijing 100083, China 3 Testing Center of Petroleum Geology, Research Institute of Petroleum Exploration and Development, Beijing 100083, China 4 Chengdu Institute of Geology and Mineral Resources, Chengdu 610082, China 

出 版 物：《Science Bulletin》 (科学通报(英文版))

年 卷 期：2007年第S1期

页      面：201-214页

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：the National Key Basic Research and Development Program of China (Grant No. 2001CB209100) 

主　　题：energy field coupling numerical modeling high-efficiency gas reservoir Feixianguan Formation Sichuan Basin 

摘      要：Through a case study of the high-efficiency gas reservoir in Feixianguan Formation in the northeast Sichuan Basin, quantitative and semi-quantitative analyses of key elements such as hydrocarbon generation, migration and accumulation, and reservoir evolution as well as their interplay in the critical moment of reservoir formation controlled by the energy field were carried out, by means of numerical modeling of the energy field. It was found that the climax time for Permian hydrocarbon generation was Late Triassic-Early Jurassic and accumulation of oil and gas has resulted in large-scale paleoreservoirs in paleostructural traps in Feixianguan Formation, a process facilitated by fractures connecting the sources. The paleoreservoirs have been turned into high-efficiency gas kitchens due to pyrolysis, which resulted from deep burial at a temperature of 170―210 ℃ as induced by tremendously thick sedimentation in the foreland basin of Daba Mountain in Late Jurassic-Cretaceous period. Meanwhile, abundant acid gas like H2S produced from thermo-chemical sulfate reduction (TSR) at high temperatures leads to extensive dissolution of dolostone in the paleoreservoirs, which may in turn result in modification of the reservoirs and preservation of the reservoir rock porosity. The present distribution of gas reservoirs was ultimately determined in the processes of adjustment, cooling and decompression of the paleoreservoirs resulting from intense deformation in the front of Daba Mountain during the Himalayan orogeny.