A major issue in many oil fields is the production of undesirable water from oil wells. One of the most important causes of unwanted water is water coning. This phenomenon may be leading to a decreasing oil production rate, an increasing water cut, and consequently high production costs. Downhole water loop (DWL) is a relatively new and effective technique to control water coning. Even though many studies have shown how effective the DWL approach is in reducing the problem of water cones, the issue of oil droplets escaping the drainage zone might damage the injection area and perhaps cause blockage. It is suggested to use the downhole oil–water separator (DOWS) approach to separate oil droplets from the water stream based on the difference in densities. This article gives a numerical analysis of DOWS in two stages. In order to confirm that the simulator could faithfully simulate this sort of separator, the findings of the employed simulator were first compared with the preceding analytical solutions. Then the impact of inlet velocities and flow rates was discussed numerically for seven scenarios in the second stage. The results showed that a high inlet velocity encourages the formation of oil droplets as a result of the mixture stream colliding with the separator walls, whereas a low inlet velocity produced undesirable results because the oil droplets remained dispersed in the water stream (the separation efficiency was 30.6% less than the high-velocity condition). In the following case, a novel design based on expanding the mixture input area and changing the mixture inlet and outlet points was presented to lessen the impact of mixture inlet velocity. The separation efficiency was improved by 38.65% as a result of this approach. Finally, the discussion's findings about the effect of mixture flow rates at the separator's inlet and upper outlet showed that the inlet rate has a bigger impact on separator performance than the upper outlet rate. The outcomes of this research and the numerical models can be utilized to enhance the system-level design, better understand this kind of separator, and increase its efficacy.

许多油田的一个主要问题是油井产生不良水。产生多余水的最重要原因之一是水锥进。这种现象可能会导致石油产量下降、含水量增加，从而导致生产成本升高。井下水环路（DWL）是一种相对较新且有效的水锥进控制技术。尽管许多研究表明 DWL 方法在减少水锥问题方面非常有效，但油滴逸出排水区的问题可能会损坏注入区域并可能导致堵塞。建议使用井下油水分离器（DOWS）方法，根据密度差异将油滴从水流中分离出来。本文对 DOWS 进行了两个阶段的数值分析。为了确认模拟器能够忠实地模拟这种分离器，首先将所使用的模拟器的结果与前面的解析解进行比较。然后对第二阶段的七种情况下入口速度和流量的影响进行了数值讨论。结果表明，高入口速度会因混合物流与分离器壁碰撞而促进油滴的形成，而低入口速度会产生不良结果，因为油滴仍然分散在水流中（分离效率比高速条件低30.6%）。在下面的案例中，提出了一种基于扩大混合物输入面积和改变混合物入口和出口点的新颖设计，以减轻混合物入口速度的影响。通过这种方法，分离效率提高了38.65%。最后，关于分离器入口和上部出口处混合物流量影响的讨论结果表明，入口流量对分离器性能的影响大于上部出口流量。这项研究的成果和数值模型可用于增强系统级设计，更好地了解这种分离器并提高其功效。