气井水力旋转射流清砂技术及其应用

A hydraulic swirling jet for sand-washing in borehole cleaning of gas wells

在不同阶段、不同井况的井筒清洁施工作业中,虽然现有的常规水力冲砂、机械捞砂、化学解堵3大类井筒清洁技术取得了较好的应用效果,但由于各项工艺技术和工具自身的局限性,不能完全满足目前低压气井清砂作业的需要。为此,研制了带整体式旋转喷头和具有滤水、防挂卡功能的大直径沉砂筒的水力旋转射流清砂工具,形成了低压气井水力旋转射流清砂工艺技术。现场应用结果表明:在井下建立了局部循环,漏失量小,对产层回压小;作业管柱不受限制;沉砂筒长度可根据需要任意组合,一次捞获量大;能彻底清洁井筒和近井地带产层裂缝,从根本上解决了井下沉积物的堵塞问题。

For the borehole cleaning at different stages and under different well conditions,although good effects can be achieved by the existing regular techniques such as conventional hydraulic sand washing,mechanical sand bailing,and chemical deplugging,all the above techniques as well as the corresponding tools show limitations,which can not satisfy the requirement of sand removal especially for low-pressure gas wells.Aiming at this problem,a hydraulic swirling jet for sand-washing is developed for the borehole cleaning of low-pressure gas wells,and its hydraulic work tools are particularly designed including an integral swirl jet nozzle and large-diameter sediment tubes with the functions of drainability and anti-sticking.Field applications show that(1) the local circulation is constructed in downhole,both leakage and backpressure are small,(2) there is no limitations on the working string,(3) lengths of the sediment tubes can be assembled and combined according to different requirements with the maximum bailed volume at each of its running time,and(4) the wellbore and fractures around and near the pay zone can be cleaned once for all,which completely prevents the downhole clogging.