Study On Distribution Of Methane In The Late Permian Coal-bearing Strata In Shuicheng-panxian-Luzhi Region; Guizhou Province, China

The coal bed methane is one of the main energy which our country develops and utilizes, in our country, the development and use of methane resources take a low proportion in the national development and use of resources, but its value is very considerable. The coals resources of Guizhou Province are abundant, its resource reserves is the sixth in the all Provinces, the coal is the source that the gas is produced, abundant coals resources can theoretically produce abundant methane resource. So we can infer Guizhou has great methane resources. The fact proves that the gas reserves of Guizhou Province are quite high, and about 3151.1 billion m3, the methane resource is the second in the all Provinces, only fewer than Shanxi Province. While coal resources of Guizhou Province mined, it will often cause a lot of gas accidents because the content of the methane is too high, not only accident causes the losses of the human lives and property, but also accident wastes a large number of resources at the same time. So the research of the methane nowadays becomes a hot study in the research field of coal resource.The study of coal bed methane in the Later Permian of Guizhou Province starts relatively late, the study degree is simple and unilateralism. It is mainly study exploration and utilization of coal bed methane resources, seldom carry on a systematic study to enrichment disciplinarian, methane enrichment region, and accident prevention in the methane (coal bed gas) enrichment region in the Later Permian of Guizhou Province.On the basis of the geological structure, the thickness of coal seem, metamorphism degree, content of methane in mine and bore, and the sediment sequence, author try to explore methane distribution in Late Permian coal-bearing strata in LiuPanShui Guizhou Province and provide a scientific data for comprehensive exploration of methane resource and prevention and control of methane accident in the coal mining in Guizhou Province. Through the research described above, author puts forward some understanding following:1. Relatively high coal metamorphism degree in studying area, the relationship between amount of methane and coal metamorphism is a positive. Coal bed virginity reflectance is general between 1.2% and 3.0% in most areas; the range of virginity reflectance of coal bed has better adsorption capacity. Therefore, large numbers of methane can be adsorbed in the coal bed.2. The floor and binching lithology of the coal seam in the studying area is mainly mudstone and shale, feature characteristics of lithology are relatively favorable to thepreservation of methane.3. There are many interval sandstone beds in coal bed series in the studying area, the sandstone beds are the favorable space that the methane is stored, which is likely to find a suitable industrial exploitation of coal gas resources.4. The fault of many blocks in the studying area is relatively development. Therefore, the tectonic stress is fairly strong, and coal micro-fracture system is development, the structures provide a good transport path for adsorbed methane in coal bed, and leads to form of high methane coal bed.5. In most of the studying areas, high gas areas are controlled by thickness of coal bed and developmental degree of press and cutting fracture structure. Then, the high gas area in the northern Fa'er may be caused by hydrogeological and Syncline of Gemudi .The low gas area in the east Fa'er may be caused by hydrogeological factor and fracture of coal (lower fracture).6. On the basis of comprehensively analysis on coal metamorphism degree, vitrinite reflectance, and the lithology of the floor and binching of coal seam, toll coal bed thickness and coal reserves, tectonics, hydrogeology and mine methane data in the studying area, author put forwards that XiangShui town-Duanjiang town -PuGu town-PuAn town is one high closure area of methane, East of FaEr town-west of BiDe town -ShangGa town -ShuiTang town is one high closure area of methane, HuaLe town-east of ShangGa town is one high closure area of methane. The three methane enrichment areas are the best prospects of methane mining, also is the key areas that should strengthen prevention and control of methane accident in coal mining course.