【作者】 陈浩； 汤达祯； 李松； 肖芝华； 李春虎； 霍祥盛； 许浩； 陶树；

【Author】 Chen Hao;Tang Dazhen;Li Song;Xiao Zhihua;Li Chunhu;Huo Xiangsheng;Xu Hao;Tao Shu;School of Energy Resources,China University of Geosciences(Beijing);Coal Reservoir Laboratory of National Engineering Research Center of CBM Development & Utilization,China University of Geosciences(Beijing);Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism,Ministry of Education;Basic Experiment Center of China United Coalbed Methane National Engineering Research Center Co.Ltd.;

【机构】 中国地质大学(北京)能源学院； 煤层气开发利用国家工程研究中心煤储层实验室； 海相储层演化与油气富集机理教育部重点实验室； 中联煤层气国家工程研究中心有限责任公司基础试验中心；

【摘要】 有效应力是控制孔隙度、渗透率的主要因素,在本文中开展了不同煤阶6个样品在有效压力为3.5～12.5MPa下的孔隙度、渗透率变化研究,并研究了气体滑脱效应在不同煤阶、不同压力下的差异变化。研究表明,随着有效应力的增加,孔隙度、渗透率表现出负指数形式的下降,低、中、高煤阶孔隙度损害率分别为29.87%、35.29%和42.45%,渗透率损害率分别为89.86%、74.24%和88.75%,;当应力卸载至初始状态,孔隙度、渗透率也无法恢复,低、中、高煤阶不可逆渗透率损害率分别为52.48%、39.39%和47.54%。气体滑脱效应对气体渗流起到积极作用,对高煤阶煤岩影响较大,同一煤岩样品中,滑脱效应贡献系数随有效应力的增加而增加。在孔隙压缩系数的定义上,推导了孔隙压缩系数计算的理论公式,并建立了渗透率预测公式。更多还原

【Abstract】 Effective stress is the main factor to control porosity and permeability.In this paper,the variation of porosity and permeability of 6 samples with different coal steps under the effective pressure of 3.5-12.5 MPa is studied,and the variation of gas slippage effect under different rank and pressure is studied.The results indicate that the porosity and permeability decrease with the increase of effective stress,and the porosity damage rates of low,middle and high rank are 29.87%,35.29% and 42.45% respectively,and the permeability damage rates are 89.86%,74.24% and 88.75% respectively.The damage rates of low,medium and high coal rank irreversible permeability are 52.48%,39.39% and 47.54% respectively.The effect of gas slipping has a positive effect on the gas seepage,and it has a great influence on the high rank coal.In the same coal sample,the coefficient of slipping effect increases with the increase of effective stress.Based on the definition of pore compressibility,a theoretical formula for calculating pore compressibility is derived and a formula for predicting permeability is established.更多还原