Abstract Strong heterogeneity and anisotropy result in complex flow and relatively low oil recovery in fractured-vuggy reservoirs. In this work, we assess the Cahn-Hilliard phase field method (PFM) and the pairwise force smoothed particle hydrodynamics (PF-SPH) method in modeling 2D multiphase flow through fracture-vug medium, in terms of different capillary numbers, mobility ratios, gravity, and wettability. Comparing the results of numerical simulations and physical experiments, the results of the PF-SPH method are closer to the physical experimental displacement process than those of the PFM, and the PF-SPH method is found to be computationally more efficient and accurate than the PFM. The experimental and numerical results reveal that when the injection velocity, represented via logarithm of the capillary number (LCN), is not greater than −4 (gas phase case) or −2.3 (water phase case) in the fracture-vug medium, the gravitative differentiation of the oil-gas or oil-water is significant, and the oil-gas or oil-water flow is a stable stratified flow. When the injection velocity LCN exceeds −3 (gas phase case) or −1.3 (water phase case) in the vertical section, the gravitative differentiation of the oil-gas or oil-water is not obvious, and the fluid flow pattern appears as an unstable jet flow.

中文翻译：

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对比相场法与成对力平滑粒子流体动力学法模拟多相流穿过裂缝孔洞介质

摘要 缝洞型油藏具有较强的非均质性和各向异性，流动复杂，采收率较低。在这项工作中，我们评估了 Cahn-Hilliard 相场法 (PFM) 和成对力平滑粒子流体动力学 (PF-SPH) 方法在模拟通过裂缝-孔洞介质的二维多相流时，根据不同的毛细管数、流动率、重力和润湿性。对比数值模拟和物理实验结果，PF-SPH方法的结果比PFM方法更接近物理实验位移过程，PF-SPH方法比PFM方法计算效率更高，精度更高. 实验和数值结果表明，当注射速度以毛细管数 (LCN) 的对数表示时，不大于-4（气相情况）或-2.3（水相情况）在缝洞介质中，油气或油水重力分异显着，油-气或油-水流是稳定的分层流。当注入速度LCN在垂直剖面上超过-3（气相情况）或-1.3（水相情况）时，油气或油水的重力分异不明显，流体流型表现为不稳定的射流。