【作者】 马强；

【导师】 郭德勇；

【作者基本信息】 中国矿业大学（北京） ， 安全技术及工程， 2011， 博士

【摘要】 通过实验研究和理论分析相结合,分析了随着煤层气储层内气体压力的降低,渗透率的变化情况,建立了渗透率预测模型。以MATCHSTICK应变为切入点,建立了结合有效应力和煤基质收缩两方面影响因素的渗透率数学分析模型(M&H模型),并通过M&H模型分析了随着孔隙内气体压力的降低,渗透率的变化规律及相应物理参数对渗透率的影响。在实验室环境下模拟Uniaxial-Strain的应力、应变条件,测量在不同孔隙压力下煤样的渗透率,通过实验数据的分析,总结渗透率的变化规律。同时通过对垂直应变的监测,论证体积不变理论的合理性。论文的研究结果对于进一步认识渗透率的变化规律,正确分析预测渗透率的变化提供理论依据,对于井田长期生产能力的评估以及煤层气开发企业做出合理的生产规划提供理论依据和技术手段。更多还原

【Abstract】 Based on both experimental and theoretical investigations, the permeability of coalbed methane reservoir is studied and analyzed with reservoir depletion. Theoretically, a new analytical permeability model is proposed using MATCHSTICK geometry and constant volume theory. The new model incorporates primarily the changes in grain and cleat volumes and is, therefore, different from the other models that lay heavy on the pore volume and cleat compressibility. The model considers the effective stress and coal matrix shrinkage effect on the permeability changes. Experimentally, the uniaxial strain condition is successfully simulated in the laboratory. The flowrate/permeability is measured by using step-wise fashion for different methane pressures. The permeability trend is analyzed for methane depletion. Moreover, the constant volume theory is valid for the coalbed methane reservoir because the vertical strain does not change in the lab-scale experiment. The study provides the theoretical basis for further analysis and perdition of coalbed methane reservoir dynamical permeability changes. It is significantly important for the coalbed methane development. It also helps CBM production companies to make long-term planning.更多还原