【作者】 李义贤；

【导师】 梁冰；

【作者基本信息】 辽宁工程技术大学 ， 流体力学， 2009， 硕士

【摘要】 煤层中的水-气两相流渗流时受有效应力和温度的共同影响,实验表明:根据有效应力原理,可以推理出,有效应力与渗透率是非线性关系。考虑到前人总结的经验公式K = K0 exp(aσ),根据大量的实验数据,做出推测:K = k 0 e aσ,T恒定时, K = k 0 e bT,σ恒定时,有K = f (σ, T)。在给出煤层气-水运移的基本假设基础上,建立考虑温度作用的气-水两相流在煤层中运移的控制方程,并在渗流过程中考虑气体扩散对渗流的影响。应用COMSOL Multiphysic对考虑温度作用的水气两相流在煤层中的运移规律进行了模拟分析。模拟了600天时,水-气两相流体在T=25℃和T=40℃时的压力场,流速场和产量。由于温度作用下的气-水两相流体在煤层中耦合作用,导致了在T=40℃时要比T=25℃时中心产气井与四周的压差变小,从而使得产气-水量下降。因此,研究低渗透煤层的渗流机理、揭示其渗流规律,并在此基础上建立考虑温度作用下的煤层气-水两相运移规律的数学模型,对于低渗透煤层气藏渗流机理的进一步研究以及气藏的高效开发与开采,不仅具有重要的理论价值,而且具有重要的实际意义。更多还原

【Abstract】 Coal seam gas-water two phase contains common influence of effective stress and temperature in seepage stage, experiment shows that according to effective stress principle, reasoning out the nonlinear relation of effective stress and permeability. Considering empirical Formula K = K0 exp(aσ), basing on massive experimental datas, it is presumed that K = f (σ, T) when K = k 0 e aσunder constant T , K = k 0 ebT under constantσ.On the base of coal seam gas-water migration basic assumption, establish gas-water two phase governing equations considering temperature influence in the coal seam and the influence of gas diffusion on seepage process. Using COMSOL Multiphysic analyzes gas-water two phase migration rule in the coal seam considering temperature action. Analyzes pressure field, velocity field and production of gas-water two phase on 600 day when T=25℃and T=40℃. In the fact that owing to gas-water two phase coupling effect considering temperature influence in coal seam, which leads to the fact that pressure difference of gas production center well becomes smaller and the surrounding production of gas-water decreases in 40 centidegree not 25 centidegree.Therefore, researching on low permeability coal seam percolation mechanism, revealing its seepage rule, on this basis estabilshing coal seam gas-water two phase migration rule mathematical model considering temperature influence, which not only has more important theoretical value, but also has more important practical significance for further research on low permeability coal seam percolation mechanism and gas reservoir efficient development.更多还原