基于LBM页岩微观尺度气体流动模拟研究

发布时间：2018-06-19 09:38

本文选题：页岩 + 气体流动　；参考：《特种油气藏》2017年03期

【摘要】：页岩有机质存在大量的微纳米孔隙,分布在该尺度孔隙中的页岩气在开采条件下的流动表现为特殊复杂的流动形态,达西渗流定律已不适用于页岩储层微纳米尺度孔隙中气体流动的模拟计算与表征。采用格子Boltzmann方法,基于页岩气微观尺度气体流动特征,结合真实气体状态方程,建立了页岩微尺度气体流动的物理模型和数学模型,得到不同参数下微观气体边界滑移速度分布和压力分布规律。计算结果表明:孔隙尺寸和压力是页岩气在微纳米孔隙中的流动能力的决定性参数,孔隙尺寸和压力的增加将导致气体压缩效应增强,滑脱效应减弱;温度升高和压力降低均能促进吸附气体发生解吸,且页岩气的解吸吸附效应对于温度的变化相对于压力更敏感。该研究对认识页岩气微观流动规律具有重要的理论价值,对制订合理的开采制度,实现页岩气长效生产具有重要指导意义。
[Abstract]:There are a large number of micro-nano pores in shale organic matter, and the flow of shale gas distributed in the pore of this scale shows a special and complex flow pattern under mining conditions. Darcy's law of percolation is no longer applicable to the simulation and characterization of gas flow in micro- and nanoscale pores of shale reservoirs. The physical and mathematical models of shale micro-scale gas flow are established by using lattice Boltzmann method based on the characteristics of shale gas microscale gas flow and the real gas equation of state. The slip velocity distribution and pressure distribution of micro gas boundary are obtained under different parameters. The results show that pore size and pressure are the decisive parameters of the flow capacity of shale gas in micro-nano pores, and the increase of pore size and pressure will lead to the enhancement of gas compression effect and the weakening of slippage effect. The increase of temperature and the decrease of pressure can promote the desorption of the adsorbed gas, and the desorption effect of shale gas is more sensitive to the change of temperature than to the pressure. This study has important theoretical value for understanding the microscopic flow law of shale gas, and has important guiding significance for formulating reasonable exploitation system and realizing shale gas long-term production.
【作者单位】：油气藏地质及开发工程国家重点实验室;西南石油大学;
【基金】：国家自然科学基金“基于页岩复杂流动行为的动态评价模型”(51401204) 国家科技重大专项“涪陵页岩气开发示范工程”(2016ZX05060)
【分类号】：TE31

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