Abstract:  Based on numerical simulation method and central composite design method， the mathematical models of the relationship among the structural parameters of downhole hydrocyclones and the separation efficiency and the underflow pressure loss were established by using the second-order polynomial function. Additional tests were carried out to compare the predicted values of the mathematical model with the actual ones of numerical simulation. The average relative errors between the predicted values and the actual ones of the separation efficiency and pressure loss are as 0.104% and 4.562% respectively， which verifies the accuracy of the prediction results of the model. Meanwhile， a comparative study was carried out on the separation performance between the response surface optimization structure and the initial structure. The results show that when the inlet oil droplet size varies in the range of 50～500 μm， the initial structural separation efficiency ranges from 58.92% to 98.56%. After optimization， the separation efficiency ranges from 60.35% to 99.48%. When the inlet water content changes in the range of 94%～99%， the separation efficiency of initial hydrocyclones increases from 74.61% to 88.07%， after optimization the separation efficiency is in the range of 75.26%～91.56%. Under the conditions of different inlet oil droplet size and water content， the optimized structure shows obvious high efficiency and applicability.

Key words: single-well injection-production, downhole hydrocyclone, structural optimization, separation performance

摘要： 基于数值模拟方法与中心组合设计方法，采用二阶多项式基函数构建了井下旋流分离器的结构参数与分离效率及底流压力损失间的数学关系模型。通过开展附加试验对模型预测值与数值模拟实际值进行对比，得出分离效率和压力损失的预测值与实际值的平均相对误差分别为0.104%和4.562%，验证了模型预测结果的准确性。针对响应面优化结果与初始结构开展分离性能对比研究，结果表明：当入口油滴粒径在50～500 μm范围内变化时，优化前结构的分离效率变化范围为58.92%～98.56%，优化后结构的分离效率变化范围为60.35%～99.48%；当入口含水率在94%～99%范围内变化时，优化前结构的分离效率由74.61%提高到88.07%，优化后结构分离效率由75.26%提高到91.56%。在不同粒径及含水率条件下，优化后结构均呈现出了明显的高效性及适用性。

关键词: 同井注采, 井下旋流分离器, 结构优化, 分离性能