Review on Coal Bed Methane Recovery Theory and Technology: Recent Progress and Perspectives

作者：Weiguo Liang, Jiwei Yan, Beining Zhang, Dongsheng Hou · 发表于：Energy & Fuels · 年份：2021 · DOI：10.1021/acs.energyfuels.0c04026 · 被引用次数：115 · 研究领域：Coal Properties and Utilization、Hydrocarbon exploration and reservoir analysis、Methane Hydrates and Related Phenomena

Coal bed methane (CBM) is a primary clean energy source found in coal seams. The recovery ratio of CBM is very low, especially with ground extraction, due to the strong adsorption of CH 4 on the pores and fissures of coal and low permeability of the coal bed. On the basis of the theory of energy balance, a theory of enhanced CBM (ECBM) recovery by energy stimulation is proposed in this review. The desorption and transportation of CH 4 in coal beds are analyzed from the perspective of energy consumption. Two pacesetting stimulation technologies are proposed to increase the permeability of coal beds: supercritical CO 2 (SCCO 2 ) fracturing and thermal fracturing through steam injection. The experimental study and the related results of SCCO 2 -enhanced CBM recovery are presented and analyzed. The results demonstrate that the permeability of SCCO 2 in the tested four ranked coal specimens decreases in the form of a negative exponent function with the increase of effective stress. The transportation capacity of SCCO 2 in high ranked coal beds deep underground is inferior to that in low ranked coal beds at shallow depth. The experiment of the total permeability of CO 2 with CH 4 in coking coal shows that the permeability decreases in the form of a logarithmic function as the content of CO 2 increases. SCCO 2 has higher transportation capacity than gaseous CO 2 in coal beds, and the total permeability decreases with its content increasing in the synthetical system with CH 4 . The S...