shale gas Calorific value of coal bed methane formation and

Coal from terrestrial higher plants, the raw coal organic matter mainly of carbohydrates, lignin, a role performed by the coal and peat coalification two stages. From plants - peat - lignite - bituminous coal - anthracite, Shale gas revolution is the result of not diagenetic - diagenesis - metamorphism - peat - Coal whole process. (Former diagenesis) peat stage, low organic matter (<50 ℃) and near-surface oxidizing environment, due to the role of bacteria to produce a small amount of methane and carbon dioxide, was soluble state or free state and lost. Lignite has entered the stage of diagenesis, is not bad coalification stage. This period is immature kerogen, ground temperature at around 50 ℃, vitrinite reflectance Ro ≈ 0.5%, the thermal degradation of organic matter and has begun to gradually deepened, biochemical gradually weakened, primarily methane and other volatiles. Bituminous phase of long-flame coal, gas coal, fat coal, coking coal, lean coal is low coalification - metamorphic stage, Ro 0.5% to 2.0%. This is the maturity of kerogen, has entered the oil threshold, sediment depth reaches 1000 ~ 4 500m, ground temperature of 50 ~ 150 ℃, the thermal degradation of organic matter through ceramic proppant manufacturers with heavy hydrocarbons, light hydrocarbons, methane and other volatile property out. Late coalification high metamorphic stage, generally lean coal and anthracite plan at this stage, Ro> 2.0%, this period is too mature kerogen, ground temperature> 150 ℃, depth> 4500m, thermal degradation products are mainly methane. 

3 calorific value 

The calorific value of coal-bed methane or gas with methane (CH4) content related to coal-bed methane extraction ground methane (CH4) content is generally greater than 96.5%, when the methane content of 97.8%, at 0 ℃, under 101.325kPa, 

Calorific value: QH = 38.9311MJ/Nm3 (about 9299 kcal / Nm3) 

LHV: QL = 34.5964MJ/Nm3 (about 8263 kcal / Nm3) 

Underground extraction of coal-bed methane proppant manufacturing (gas) will generally methane (CH4) content of 40.8%, after adjustments to take advantage of this time the heat value of gas: (at 0 ℃, 101.325kPa under) 

LHV: 14.63MJ/m3 (about 3494 kcal / Nm3)