聚合物分压注入工具结构优化设计

Structural Optimization Design of Polymer Partial Pressure Injection Tool

大庆油田采用聚合物驱单管多层注入工艺开发低渗透油田。该技术利用分质工具调整聚合物相对分子质量以匹配油层渗透率,利用分压工具对聚合物溶液注入压力进行控制。为提高分压工具对注入聚合物溶液压力调控范围,达到最佳降压效果,基于数值模拟软件fluent对比了不同结果参数组合的分压工具的压力分布、速度分布及湍动能分布,对分压工具结构进行优化设计。设计结果表明：降压槽在非颈部流体速度呈层状分布,起分压作用的主要部位是在环隙空间最小截面处,降压槽槽数为12的环形降压槽比槽数为6的降压槽分压效果更好,环形降压槽的槽数和分压效果成正相关;直径为18mm的环形降压槽比直径为17mm的环形降压槽分压效果差,动态表现为在整体压力减小的趋势下,后者的梯度更大,降压槽直径和分压效果成负相关。对比设计的3种环形降压槽,槽数为12、直径为17mm的环形降压槽的分压效果为最佳。该结果能够为分压工具在工程上的应用提供理论支持。

The monotube layered injection technology in polymer flooding was applied to the development of Daqing low-permeability oilfields.The technology uses the different medium injection tool to adjust the molec-ular weight of the polymer to match the permeability of the reservoirs,and uses the partial pressure tool to control the injection pressure of the polymer solution to realize the purpose of improving the control range of the injection pressure and achieving the best effect of the pressure drop.The structure of the partial pressure tool was optimized based on the numerical simulation software fluent through the comparison of the pressure distribution,velocity distribution and turbulent kinetic energy distribution of the partial pressure tool with dif-ferent combination of the result parameters.The design results show that the non-neck fluid velocity in the depressurization groove was layered.The main parts of the partial pressure were in the minimum cross-section of the annulus space,and the annular depressurization groove with the number of 12 is better than that with6,and the number of the annular depressurization groove and the partial pressure effect were positively corre lated.The annular depressurization groove with a diameter of 18 mm is less effective than that with the diameter of 17 mm,and the dynamic performance is that the gradient of the latter is larger under the trend of overall pressure drop,and the diameter of the annular depressurization groove and partial pressure effect were nega-tively correlated.After the designed three types of the annular depressurization grooves were compared,it was known that the annular depressurization groove with the groove number of 12 and the diameter of 17 mm was the best.The results can provide theoretical support for engineering application of the partial pressure tool.