论文部分内容阅读
非常规油气资源的孔隙结构及其连通性非常复杂,其孔隙尺度从毫米到纳米跨越多个量级.多孔介质中气体的输运过程不仅依赖于介质的多尺度微观结构特征,还依赖于气体的相关属性.气体在多尺度多孔介质中的输运过程包括无滑流、滑脱流和过渡流,涉及分子扩散和努森扩散等多种机制,因此很难用唯一的连续介质理论来描述气体的输运特征.大量的数据表明真实多孔介质中的内部孔隙具有分形标度特征,因此采用分形几何表征多尺度多孔介质的孔隙结构,引入孔隙分形维数和迂曲度分形维数定量表征多孔介质的微结构和弯曲流道,建立多尺度多孔介质气体输运过程的细观模型;推导了多尺度多孔介质中气体的有效渗透率和有效扩散系数,并讨论了多尺度多孔介质微结构参数和气体属性对于气体等效输运特性的定量影响.该研究不仅可以丰富渗流理论,且有利于深入理解非常规油气藏的产出机制.
The unconventional oil and gas resources have very complicated pore structure and connectivity, and their pore sizes range from millimeter to nanometer. The transport of gas in porous media depends not only on the multi-scale microstructure of the medium, but also on the gas The transport properties of gas in multi-scale porous media include non-slip flow, slip flow and transition flow, and involve many mechanisms such as molecular diffusion and Knudsen diffusion. Therefore, it is very difficult to describe the gas with the unique continuum theory A large number of data show that the internal porosity in real porous media has the characteristics of fractal scale. Therefore, the fractal geometry is used to characterize the pore structure of multi-scale porous media. The porous fractal dimension and tortuosity fractal dimension are introduced to quantitatively characterize the porous media And the microscopic structure of the multi-scale porous media were established. The mesoscopic model of gas transport in multi-scale porous media was established. The effective permeability and effective diffusion coefficient of gas in multi-scale porous media were deduced. The microstructure parameters of multi- The quantitative effect of gas properties on gas equivalent transport properties.The study not only enriches seepage theory but also benefits Output understand the mechanism of unconventional reservoirs.