高压防返吐挤堵管柱及配套工具研究

Research of High-pressure Back-flow Preventing Squeeze String and Accompany Tools

为了提高高压挤注堵剂工艺成功率,降低施工风险,研究了高压防返吐挤堵管柱及配套工具。高压防返吐挤堵管柱由63.5 mm油管、安全接头、反洗阀、插管保护器和防返吐插管封隔器组成。防返吐插管封隔器底部下接头采用锥形设计,可防止被堵剂固住,便于起出;插管密封采用多级组合式密封,可保证密封的有效性和长效性;插管密封上端设计保护胶筒,可有效防止上部油套环空漏失物向下沉积。现场应用结果表明,该管柱解决了高压挤注难、封隔器密封效果差、施工风险高和斜井起下难度大等问题,满足油田高压挤注堵剂封堵施工要求。

In order to improve the success rate and reduce the risk of high-pressure squeeze operation, the study of high-pressure back-flow preventing squeeze string and it＇ s accompany tools have been conducted. The high-pressure back-flow preventing squeeze string consists of 063.5 mm tubing string, safety joint, backwash valve, intuhate protector and flow-back prevention intubate packer. The tapered design of lower sub at the bottom of flow-back prevention intubate packer can prevent the pack been cemented by plugging agent and is convenient for pulling out. The multistage modular seal is adopt in intubate seal to ensure the effectiveness of the seal and prolong the sealing time. A protective rubber tube is designed at the top of the string, which can effectively prevent the deposition of matters from the upper part of annulus. Field application results show that the string has addressed the pre- vious problems like difficult high-pressure squeeze, poor packer seal, high operation risks, difficult tripping in de- viated hole, meeting the requirements of oil field for high-pressure squeeze operation.