Constraints of methane absorbability in the Upper Permian Longtan Formation of Well DC-5 in Guxu mine area of southern Sichuan Coalfield [川南煤田古叙矿区DC-5井上二叠统龙潭组煤层甲烷吸附性及其主控因素]

作者：Bao Y.; An C.; Ju Y.-W.^*; Yin Z.-S.; Xiong J.-L.; Wang W.-B.

来源：天然气地球科学, 2020, 31(1): 93-99.

DOI：10.11764/j.issn.1672-1926.2019.10.011

• Constraint
• Guxu mine area
• Longtan Formation
• Methane adsorption
• South Sichuan Coalfield

Research on the absorbability of coalbed methane is of importance for guiding the exploration and exploitation of coalbed methane and revealing the storage mechanism of coalbed methane. This study investigates the coal quality and methane adsorption capacity at different depth of the Longtan Formation in the Guxu mine area of southern Sichuan Coalfield by drilling sampling, coal rock and coal analysis, and methane isothermal adsorption testing. The main geological factors affecting methane adsorption capacity are analyzed using a multiple linear stepwise regression method. Results show that the coal rank of the Longtan Formation in the Guxu mine area has reached the anthracite stage(Ro, max ranges from 2.83% to 3.22%), which belongs to high-rank coals. Vitrinite is the main component of coal maceral and followed by inertinite without exinite. Clay mineral is the main component of the inorganic mineral. The difference of moisture and volatile matter contents between coal seams in the Longtan Formation is small, while a large difference between ash and fixed carbon contents is observed. Langmuir volume(VL)of different coal seams ranges from 11.39 to 25.06 m3/t. Fixed carbon content is the main factor affecting the methane adsorption capacity of the coal seams in the Guxu mine area. The content of fixed carbon is positively correlated with the methane adsorption quantity.

• 单位
  中国科学院大学