DataSheet1_Research on Boundary Layer Effect in Fractured Reservoirs Based on Pore-Scale Models.docx

It is of great significance to study the seepage characteristics of heavy oil reservoirs, which are conducive to the efficient development of resources. Boundary layer effect (BLE) exists in the pore-scale flow process of macromolecular fluid media, which is different from the flow law of conventional fluid in the pore, yet the influence of BLE is ignored in the previous pore-scale simulation. Conventional porous media simulations have difficulty analyzing the mass transfer law of small-scale models under the influence of microfractures. Based on the CT scanning data and thin section data of the real core in the target area, the rock skeleton and flow space were extracted according to the maximum ball algorithm, and the pore network model representing the complex structure was constructed. The microscale effect of macromolecules in the flow process in the pores was characterized by modifying the effective flow. The effects of the BLE on the effective connectivity, displacement process, and oil distribution law were analyzed. The seepage characteristics of different wettability conditions and different water cut stages were compared. The results show that BLE reduces the effective flow space and leads to deviations in the relative permeability curve and capillary curve. For fractured porous media, the irregular shape of porous media was characterized by the morphological method, and the mass transfer process was analyzed by the equivalent flux method. The influence of the porous media shape on the macromass transfer process was compared. This study provides a solution to the problem of BLE in pore-scale simulation.

研究重油储层渗流特性具有重要意义，这不仅有助于资源的有效开发。在宏观流体介质的多孔尺度流动过程中，存在边界层效应（BLE），与孔隙中传统流体的流动规律不同，然而，在先前的多孔尺度模拟中，BLE的影响被忽略。传统的多孔介质模拟难以分析在微裂缝影响下的微观模型的质量传递规律。基于目标区域实心岩心的CT扫描数据和薄片数据，根据最大球算法提取了岩石骨架和流动空间，构建了代表复杂结构的孔隙网络模型。通过修改有效流动，表征了流动过程中大分子在孔隙中的微观效应。分析了BLE对有效连通性、位移过程和油分布规律的影响。对比了不同润湿条件和不同含水率阶段的渗流特性。结果显示，BLE降低了有效流动空间，导致相对渗透率和毛细曲线出现偏差。对于裂缝性多孔介质，通过形态学方法表征了多孔介质的非规则形状，并利用等效通量法分析了质量传递过程。比较了多孔介质形状对大质量传递过程的影响。本研究为解决多孔尺度模拟中的BLE问题提供了解决方案。