How does natural gas exist underground?
In the total amount of resources, the Cenozoic accounted for 37.3%, Mesozoic group of the upper Paleozoic, the upper Paleozoic of the world, the lower Paleozoic of the year 25.5%, 26.1%. The genetic type of natural gas resources, high maturity of the pyrolysis gas and coalbed methane dominated respectively of the total amount of resources 28.3% and 20.6%, oil gas in coalbed gas accounted for 18.8%, accounted for 27.6%, accounting for 4.7% of biogenic gas. Chinese natural gas reserves are concentrated in 10 large basins, followed by: Bohai, Sichuan, Junggar, Songliao, Yinggehai and Qiongdongnan, Qaidam Basin, Turpan, Tarim, Bohai, Ordos. The gas fields in China are mainly small and medium, and the geological structures of most gas fields are complex. 1991-1995, China's natural gas production increased from 16 billion 73 million M3 to 17 billion 947 million m3, with an average annual growth rate of 2.33%.
The sedimentary rocks in China are widely distributed in the continental basins, forming a variety of favorable geological conditions for natural gas storage. According to the forecast of natural gas resources in China in 1993, China's total natural gas resources amount to 38 trillion m3, the onshore natural gas is mainly distributed in the central and western regions, accounting for about 43.2% of the land resources and the total amount of natural gas resources, respectively, and the total amount of natural gas resources in China is 39%. The distribution of the natural gas resources in China is dominated by the Cenozoic third and Paleozoic strata
Natural gas is a kind of mixed gas which is the main body in the underground rock reservoir. Including oil field gas, gas field gas, coal bed gas, mud volcanic gas and biological gas. The main component is methane, usually 85-95%; followed by ethane, propane, butane, etc.. It is a good fuel and chemical raw materials. The gas is usually volatile fraction of crude oil, the gas exists in the form of reservoir, where there are oil formation, oil and gas are different proportion. Even in the same field of oil and gas sources are not necessarily the same. They are collected from different pathways and different processes in the same reservoir. If you are a non associated gas and liquid concentration independent, may be produced in plant material. The world's natural gas production is mainly gas and gas. The exploitation of coalbed methane has been paid more and more attention.
