应力对煤岩裂缝宽度及渗透率的影响
The effects of stress on fracture and permeability in coal bed
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摘要: 煤层气的开发实践表明,煤岩裂缝和渗透率是制约我国煤层气资源开发成败的关键因素之一。以室内实验为手段,系统研究了有效应力改变条件下煤岩裂缝宽度和渗透率的变化规律。结果表明:煤岩裂缝宽度和渗透率都随有效应力的增大而减小;当有效应力达到8 MPa后,裂缝宽度变化相对缓慢,渗透率变化也很微弱。由此可见,煤岩裂缝和渗透率对应力的变化非常敏感。Abstract: The development of coalbed methane shows that fracture and permeability of coal bed are two key factors on the success development of China's CBM resource.The paper systematically studied the change law of fracture width and permeability as stress varied in laboratory experiments.The results showed that fracture width and permeability continuously decreased in the process of increasing effective stress;fracture width and permeability changed very slowly when stress reached to 8 MPa.Thus,fracture and permeability of coal bed are very sensitive to stress.Results showed that coal bed had strong stress-sensitivity.