摘要
为了揭示煤系中煤层、泥页岩、致密砂岩覆压下的孔隙度和渗透率差异变化特征,采集山西沁水盆地古县区块2块煤样、2块泥页岩和4块砂岩样品,开展了覆压孔渗对比实验研究。结果表明煤系"三气"储层覆压下孔隙度与渗透率随有效应力增加呈负指数形式减少,煤储层、泥页岩储层、致密砂岩储层孔隙度压缩系数比值为1∶1∶0.58,渗透率衰减系数比值为1∶0.73∶0.78。"三气"储层孔隙度、渗透率应力损害率随有效应力增加呈两段式增加,有效应力<4MPa,"三气"储层孔隙度和渗透率损害率均随有效应力的增大呈快速增大的趋势,有效应力>4MPa,随有效应力的增大增幅逐渐平稳,煤储层、泥页岩储层、致密砂岩储层应力敏感性依次降低。研究成果对煤系"三气"的共探共采具有理论意义和实际意义。
In order to reveal the characteristics of the difference in porosity and permeability of coal,shales and tight sandstones in coal series,2 coal samples,2 shale samples,and 4 sandstone samples were collected from the Guxian County,Qinshui Basin,Shanxi Province,and a comparative study of the net confining stress permeability was conducted.The results show that the porosity and permeability of three natural gases in coal series reservoirs increase exponentially with the increase of effective stress,and the ratio of porosity compressibility of coal reservoirs,shale reservoirs and sandstone reservoirs is 1∶1∶0.58,the permeability attenuation coefficient ratio is 1∶0.73∶0.78.The porosity and permeability stress damage rate of three natural gas reservoir increase with the increase of effective stress in the form of two-stage,and the effective stress is4 MPa.The porosity and permeability damage rate of three natural gases reservoir both follow the effective stress.The increase shows a rapid upward trend with an effective stress of 4 MPa.With the increase of effective stress,the growing rate is gradually stable,and the stress sensitivity of coal reservoirs,shale reservoirs,and sandstone reservoirs decreases sequentially.The research results have theoretical and practical significance for the co-examination of the three natural gases in coal series.
作者
程鸣
傅雪海
张苗
程维平
渠丽珍
Cheng Ming;Fu Xue-hai;Zhang Miao;Cheng Wei-ping;Qu Li-zhen(School of Resource and Earth Science,China University of Mining and Technology,Ministry of Key Laboratory of Coalbed Methane Resources and Reservoirs,Xuzhou 221116,China;Shanxi Provincial Research Institute of Geology and Mineral Resources,Taiyuan 030001,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2018年第8期1163-1171,共9页
Natural Gas Geoscience
基金
国家自然科学基金项目(编号:41772158)
山西省煤基重点科技攻关项目(编号:MQ2014-02)联合资助
关键词
煤系“三气“储层
覆压
孔隙度
渗透率
应力敏感性
Three natural gases in coal series reservoirs
Net confining stress
Porosity
Permeability
Stress sensitivity
