高效洗井防污染管柱的研究与设计

Research and design of tubing strings for well flushing and formation damage prevention

针对“三低”油井或结蜡油井采用常规加药和周期性热洗井易造成油层污染而影响产量的问题,研究设计了一趟高效洗井防污染管柱。该趟管柱主要由Y441型液压封隔器、侧向旁通补偿器、过压式固定阀等组成。中原油田采油四厂、采油五厂15井次的现场应用表明,试验成功率和合格率均为100%,不仅解决了周期性热洗对油层的伤害问题,而且热洗后排液时间提前了3d,平均单井年节约成本7.2万元。

In consideration of the problems of the influence of formation damage caused by conventional dosage and cyclical thermal well flushing on the production output in 'three lows' and paraffin-troubled wells, a tubing string is designed for high efficient well flushing and preventing formation damage. It is composed of Y441 hydraulic packer, sideway bypass compensator and a fixed overpressure valve. It is used in 15 wells in No.4 and No.5 Oil Production Plants of Zhongyuan Oilfield. The field application shows that the success rate and qualification rate of the field test are 100%. It can be used to solve the problem of formation damage caused by cyclic thermal well flushing, also the period of liquid discharging after thermal flushing is obtained 3 d ahead of schedule. 72 thousand Yuan RMB of average single well cost is saved yearly.