Shale gas, a kind of free or adsorbed state hiding in shale or mudstone in unconventional gas

Shale gas, a kind of free or adsorbed state hiding in shale or mudstone in unconventional gas
    shale gas , are becoming agitated world market forces. This is the international energy community called "game changer" for  Unconventional gas   greatly changed the world energy. Especially occur in  unconventional gas   Is also dense shale rock, it can also be classified as tight gas gas. Industrial development is only achieved success in North America (mainly the United States). It began in the Appalachian Basin Devonian shale, is dark brown and black, organic-rich, can be a lot of angry. Cracks in the main reservoir space, and in the form of adsorbed gas and water soluble gas occurrence, is low (negative) pressure, low saturation (about 30%), and thus for the low yield. But in fracture zone receive higher yield, underground explosions and rehabilitation measures  Hydraulic fracturing  effect is good. The mid-1990s has been expanded to Michigan and Illinois basins, producing layers extend to the Lower Carboniferous shales, production reached 8.4 billion cubic meters. Amount of its resources up to several trillion cubic meters.
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        shale gas is mined from shale in natural gas, the main carbon in dark shale or clay shale, shale gas is adsorbed on the body in order to exist in the free state or mudstone, carbon mudstone, shale and pink sandy rocks dissection of natural gas, which can be generated in various stages of organic origin on the body in the free gas phase (about 50%) present in the cracks, porosity and other reservoir space to adsorb state (about 50%) present in kerogen, clay particles and pore surfaces, a very small amount to dissolve the state is stored in kerogen, bitumen and petroleum. Natural gas is also present in sandwich-like siltstone, silty mudstone and muddy siltstone, sandstone formations even. Gas generation later, in the nearest source rocks gathered, the performance of a typical in-situ forming pattern, and oil shale, oil sands, bitumen and other varied. Different from conventional reservoirs with gas, shale gas is both generated source rocks, but also accumulation and preservation of natural gas reservoir and cap rock. Therefore, the high content of organic matter in black shale, mudstone carbon is often the best development of shale gas Pieces.
       shale gas  evelopment has extensive geological significance, present in almost all of the basin, just as the burial depth, gas saturation, etc. greatly different industries have different values. Chinese traditional shale fractured gas shale reservoirs, fractured shale reservoirs, fractured reservoirs such as fairly broadly in line with this, but none of them consider the adsorption mechanism of action is not considered one of the native natural gas properties, and in the understood as a body gathered in the cracks in the shale oil and gas in free phase. Therefore incomplete sense of belonging to shale gas. Therefore, China's fractured shale reservoirs concept and connotation of shale gas in the United States today are not the same, respectively, in the content of hydrocarbon substances, storage phase, the source characteristics and ingredients so there is a big difference.