Microscopic Analysis of Flow Resistance of Oil Displacement Fluid in Reservoir Fractures

The flow resistance of displacement fluids within reservoir fractures directly influences oil recovery efficiency and sweep efficiency, thereby exerting a substantial impact on reservoir recovery and overall oilfield production. To address the significant flow resistance of contemporary displacement fluids, this study developed a multi-performance evaluation apparatus capable of simultaneously measuring fluid viscosity, flow resistance, and displacement efficiency. The effects of various reservoir parameters and fluid compositions on flow resistance and sweep area were systematically analyzed. Elevated reservoir temperatures clearly reduce fluid flow resistance within fractures, allowing displacement fluids to penetrate more deeply into the reservoir. In contrast, an inverse relationship between reservoir pressure and flow resistance was observed, which poses a significant barrier to reducing flow resistance and achieving rapid fluid penetration. Moreover, through a micromolecular perspective and adsorption theory, this study identifies strategies to modify flow resistance, thereby substantially enhancing displacement efficiency and sweep area by lowering flow resistance. This study provides foundational data and a theoretical framework for mitigating fluid flow resistance within reservoir fractures during oil recovery, thereby facilitating enhanced oil recovery over a larger reservoir area.