A Pore-Skeleton-Based Method for Calculating Permeability and Capillary Pressure
A Pore-Skeleton-Based Method for Calculating Permeability and Capillary Pressure
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基于孔隙骨架的渗透率和毛管压力计算方法
DOI：
10.1007/s11242-018-1095-1
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发表时间：
2018
影响因子：
2.7
通讯作者：
Wang Xin
中科院分区：
文献类型：
--
作者：
Li Xinling;Jiang Zeyun;Ma Jingsheng;Wang Xin
我们发展了一种从裂隙岩石模型中提取的孔隙骨架计算渗透率和毛管压力的新方法，该骨架可能包括基质孔隙的中轴和/或裂缝孔洞的内侧表面。因此，这样的骨架能够封装孔隙-空隙空间中全部相连的流体流动路径。为了进行孔隙网络流动模拟，需要进一步将孔隙骨架离散成由相互连接的节点和键组成的网络，以捕捉局部孔隙形态。蒋等人(ADV Water Resour 107：280-289,2017)开发了一种提取这种类型的孔隙骨架的方法，并提出了一种离散化方法来构建在许多方面都是最优的孔隙网络模型。在这项工作中，我们开发了一种新的就地离散化方法，通过在每对骨架体素之间简单地插入一个虚拟链接，一个键，在某些条件下，这些骨架体素或节点要么是面，要么是边相邻的。这种新方法得到了一个更简单的孔网络模型，即虚拟网络，其中每个节点或键被假定为一个圆柱体或一个微小的断裂，并且只规定了长度和内切半径/孔径。因此，还开发了一个更简单的孔隙网络模拟器，根据每个虚拟链接落入的位置使用改进的电导和毛细压力公式，适当地区分基质或裂缝中的每一种局部构型。我们通过将模拟结果与格子Boltzmann方法和实验室泛洪实验的结果进行比较，验证了我们的方法，并通过灵敏度分析证明了我们方法的准确性和有效性。
We have developed a new method for calculating permeability and capillary pressure from the pore skeleton that is extracted from a fractured rock model, which might comprises medial axes of matrix pores and/or medial surfaces of fracture voids. Such a skeleton, therefore, is able to encapsulate the total connected fluid flow paths in the pore-void space. To do pore-network flow simulations, the pore skeleton needs to be further “discretised” into a network of interconnected nodes and bonds to capture local pore morphology. Jiang et al. (Adv Water Resour 107:280–289, 2017) developed a method to extract pore skeletons of this type and a discretisation to construct a pore-network model that is optimal in many aspects. In this work, we develop a new in-place discretisation method, by simply inserting a virtual link, a bond, between every pair of skeleton voxels, nodes, which are either face or only edge adjacent under certain conditions. This new method results in a simpler pore-network model, i.e. a virtual network, in which each node or bond is assumed as either a cylinder or a tiny fracture, as well as prescribed with length and inscribed radius/aperture only. As a result, a simpler pore-network simulator is also developed using improved formulae of conductance and capillary pressure according to where each virtual link falls, appropriately distinguishing every local configuration within matrixes or fractures. We verify our methods by comparing the simulation results against with those of lattice Boltzmann methods and a laboratory flooding experiment and demonstrate the accuracy and efficiency of our methods with sensitivity analysis.