旋转射流联合沉砂筒解堵工艺关键参数研究

部分油气井因井漏失返而无法建立全井循环,传统解堵工艺难以解决此类油气井的堵塞,为此开展了旋转射流联合沉砂筒解堵工艺研究.旋转射流联合沉砂筒解堵工艺是利用油管将高压水输送至旋转喷头形成旋转射流,破碎井底堵塞物,堵塞物被上返液运送至一定高度,在环空液柱升高漏失量增大或停泵等因素影响下,堵塞物沉积在旋转喷头上方的沉砂筒内,随着沉砂筒起出带至地面.利用固液两相流体力学对堵塞物进行了受力分析,推导出不同类型的堵塞物上返所需流速的计算公式,并根据力矩平衡原理推导出了旋转喷头正向喷嘴水力参数计算公式.卧51井采用旋转射流联合沉沙筒解堵工艺进行冲砂解堵,15 min冲砂进尺达9.98 m,解堵效果良好,表明该工艺可以较好地解决低压油气井堵塞的问题,为油气井解堵提供了新思路. 

Key Parameters of Removing Blockage with Rotating Jets and Sand-Tubes

Whole-well circulation could not be built up for some oil and gas wells due to low pressure,and easy circulation loss and traditional blockage removing could not be used to clean these wells.In this paper,a novel technique was implemeneted,which involved a new plug removal technology,in which high pressure water through an oil tube rotates the nozzle,and rotating jets were formed to break up the blocking-mass.The broken blocking-mass would move up in water drive.When the leakage increased or pumping stopped,the blocking-mass would deposit in the sand-tube above the rotating nozzle and be brought to the ground with the sand-tube.A forced analysis of the blocking-mass was studied by solid-fluid mechanics,and the return flow rates with different silt styles were presented.The equation for calculating hydraulic parameter of rotating nozzle was derived by the moment balance theory.This plug removal technology was applied in Well Wo-51,and the blocking-mass of 9.98 meters was cleared in 15 min.It showed that the removing blockage with rotating jet and sand-tube turned out to be an effective blockage removing method for wells with low pressure and easy circulation loss.It would provide a novel means to plug removal.