气井井下防砂工作筒冲蚀性能研究

为降低气井压裂后出砂对生产管柱及地面设备造成的危害，延长气井生产管柱使用寿命，提高生产安全性，研发了气井井下防砂工艺技术。研制的工作筒作为防砂筛管井下定位的关键部件，在压裂过程中受高速支撑剂颗粒冲蚀作用而磨损，其定位可靠性存在风险。为研究工作筒的冲蚀规律，运用数值模拟软件对工作筒在不同排量、砂比、粒径条件下的冲蚀情况进行分析。研究结果表明：支撑剂对工作筒的冲蚀磨损主要发生在筒内变径区域；随着施工排量的增加，工作筒的冲蚀速率随之增加，且成近似指数关系；在施工排量及砂比一定的条件下，颗粒直径变大，冲蚀磨损呈现出先增大后减小的趋势。分析结果可为防砂工作筒结构的优化设计提供依据。

Study on Erosion Performance of Downhole Sand Control Working Cylinder in Gas Wells

In order to reduce the harms caused by sand production after fracturing to production string and ground equipment, prolong the service life of production string and improve production safety, Daqing oilfield has developed the downhole sand control technology of gas wells. As the key component of the downhole positioning mechanism of the sand control screen, the working cylinder developed by the technology is eroded by high-speed proppant particles during the fracturing process, and its positioning reliability is at risk. In order to study the erosion law of the working cylinder, the numerical simulation software was used to analyze the erosion situation of the working cylinder under different displacements, sand ratios and particle sizes. The research results show that the erosion wear of the working cylinder mainly occurs in the internal diameter changing area. With the increase of the construction displacement, the erosion rate of the working cylinder increases with an approximate exponential characteristic. Under the condition of certain construction displacement and sand ratio, the particle diameter becomes larger, and erosion wear tends to increase first and then decrease. The analysis results provide a theoretical basis for optimization design of the working cylinder structure.