Petroleum Science >2015,??Issue 4:??684-691 DOI: https://doi.org/10.1007/s12182-015-0054-5
Characteristics and control mechanisms of coalbed permeability change in various gas production stages Open?Access
文章信息
School of Energy Resources, China University of Geosciences, Beijing 100083, China Coal Reservoir Laboratory of National Engineering Research Center of Coalbed Methane Development & Utilization, Beijing 100083, China;School of Energy Resources, China University of Geosciences, Beijing 100083, China Coal Reservoir Laboratory of National Engineering Research Center of Coalbed Methane Development & Utilization, Beijing 100083, China;School of Energy Resources, China University of Geosciences, Beijing 100083, China Coal Reservoir Laboratory of National Engineering Research Center of Coalbed Methane Development & Utilization, Beijing 100083, China;School of Energy Resources, China University of Geosciences, Beijing 100083, China Coal Reservoir Laboratory of National Engineering Research Center of Coalbed Methane Development & Utilization, Beijing 100083, China;School of Energy Resources, China University of Geosciences, Beijing 100083, China Coal Reservoir Laboratory of National Engineering Research Center of Coalbed Methane Development & Utilization, Beijing 100083, China;School of Energy Resources, China University of Geosciences, Beijing 100083, China Coal Reservoir Laboratory of National Engineering Research Center of Coalbed Methane Development & Utilization, Beijing 100083, China;School of Energy Resources, China University of Geosciences, Beijing 100083, China Coal Reservoir Laboratory of National Engineering Research Center of Coalbed Methane Development & Utilization, Beijing 100083, China
文章摘要
coalbed methane (CBM) production data of Fanzhuang
block in southern Qinshui basin, the dimensionless gas
production rate is calculated to quantitatively divide the
CBM well production process into four stages, i.e., drainage
stage, unstable gas production stage, stable gas production
stage, and gas production decline stage. By the
material balance method, the coal reservoir permeability
change in different stages is quantitatively characterized.
The characteristics and control mechanisms of change in
coalbed permeability (CICP) during different production
stages are concluded on five aspects, i.e., permeability
trend variation, controlling mechanism, system energy,
phase state compositions, and production performance. The
study reveals that CICP is characterized by first decline,
then recovery, and finally by increase and is controlled
directly by effective stress and matrix shrinkage effects.
Further, the duration and intensity of the matrix shrinkage
effect are inherently controlled by adsorption and desorption
features.
關鍵詞
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Production stage Coalbed methane Permeability Dynamic change Control mechanism