论文部分内容阅读
为了探讨在煤层气排采过程中煤储层渗透率的动态演化规律,以松藻煤矿K2煤层煤样制作的型煤试件为研究对象,进行了不同应力、温度作用下煤渗透率随气体压力降低演化规律的试验研究。研究结果表明:煤的渗透率随气体压力下降基本呈现先减小后增大的趋势,渗透率最小值对应的气体压力临界值将渗透率随气体压力的演化分为2个阶段;根据气体压力敏感系数Cp定义,不同围压温度条件下气体压力敏感系数与气体压力呈现对数关系;由于有效应力与基质收缩效应2方面的影响,在初始阶段随围压及温度的升高煤渗透率对气体压力的响应程度增大,基于气体压力敏感系数建立了气体压力与渗透率的关系式,可为合理制定煤层气排采方案提供指导。
In order to investigate the dynamic evolution of permeability of coal reservoirs during coalbed methane drainage, taking briquette samples made from coal samples of K2 seam in Songzao Coal Mine as the research object, the permeability of coal under different stresses and temperatures was studied. Experimental Research on Evolution of Pressure Decreasing. The results show that the permeability of coal decreases with the decrease of gas pressure and then increases. The critical value of gas pressure corresponding to the minimum permeability divides the permeability into two stages with the evolution of gas pressure. According to the gas pressure Sensitivity coefficient Cp definition, gas pressure sensitivity coefficient under different confining pressure temperature and gas pressure showed a logarithmic relationship; due to the effective stress and matrix contraction effect of two aspects, with the initial stage of the confining pressure and temperature increase of coal permeability The response of gas pressure increases. Based on the gas pressure sensitivity coefficient, the relationship between gas pressure and permeability is established, which can provide guidance for the reasonable formulation of CBM draining plan.