关键词: 开平煤田, 煤层气, 构造演化, 岩浆侵入, 逆冲推覆构造, 地质演化史

Abstract: Kaiping coal-field is a typical area of synclinal control of gas development. In order to investigate the history of CBM geological evolution, this article analyzes structural characteristics and its evolution and coal quality of the coal-field, discusses the gas-bearing property, and simulates burial-generation history of the main coal seams. The results show that because of the influences of coal burial conditions and late tectonic movements, there is different history of CBM geological evolution in different structural positions of Kaiping coal-field, which can be mainly divided into three types: Tangshan mine type, Lujiatuo mine type and Donghuantuo mine type. The former two types experience twice coal generation processes, due to the influences of thrust nappe structure, there are good CBM storage conditions of Tangshan mine type, which present CBM is the richest; Donghuantuo mine type experience once coal generation process, which structural conditions are simple. The CBM is rich in the middle of NW part of Kaiping Syncline where tectonically deformed coals develop. Contrarily, the CBM loses too much in other area, which results in the lowest CBM content; Lujiatuo mine type has a greater degree of coal metamorphism influenced by magmatic intrusion in advanced Yanshanian epoch, which present CBM content is between Donghuantuo mine type and Tangshan mine type.