海上油田分层开采压力膨胀式插入密封技术

Pressure expansion insert seal technology for separate zone production in offshore oilfield

高永华 陈钦伟 刘华伟 高宁波 于洪旭

GAO Yonghua CHEN Qinwei LIU Huawei GAO Ningbo YU Hongxu

中海石油(中国)有限公司天津分公司 中海油能源发展股份有限公司工程技术分公司

CNOOC Tianjin Branch Company, Tianjin 300452, China CNOOC EnerTech-Drilling & Production Co., Tianjin 300452, China

针对海上油田油水井分层开发开采时出现的井下防砂密封筒磨损、划伤及腐蚀等原因造成的与插入密封之间密封失效问题，设计了一种具有主动密封功能的压力膨胀式插入密封，此新型密封通过井下管柱内加压使其受压膨胀后与井下密封筒过盈配合，使密封单元主动与井下密封筒达到密封状态，实现分层目的。解封时膨胀单元自动恢复原状实现顺利解封，解决了使用常规插入密封无法正常分层开发开采的难题。现场应用后通过钢丝压力计分层验封结果表明，该压力膨胀式插入密封与常规插入密封相对比，密封效果好，工艺成功率高，能够实现与井下受损密封筒的有效密封，避免了油水井二次完井防砂带来的大量人力物力消耗，为海上油田油水井的分层开发开采提供了技术保障。

When separate zone production is conducted in the oil and water wells of offshore oilfields, the seal between the insert seal and the downhole sand control seal bore is failed due to the abrasion, scuffing and corrosion of the downhole sand control seal bore.In this paper, a pressure expanding insert seal with the function of active sealing was designed to deal with this seal failure. This new seal is expanded under the pressure inside the downhole string and is in interference fit with the downhole seal bore, and the sealing element activelу reaches the sealing state with the downhole seal bore. And thus, the zones are separated. To unset, the expansion unit recovers to the original state automatically and unsetting is realized smoothly. Thus, the difficulty that the conventional insert seal is not available for separate zone production is solved. The separate zone seal testing results obtained by slick line pressure gauge after field application shows that compared with the conventional insert seal, this pressure expanding insert seal is better in sealing effect and higher in process success ratio. Bу virtue of this pressure expanding insert seal, the damaged downhole seal bore is sealed effectivelу and abundant labor power and resource consumption caused bу sand control in the secondarу completion of oil and water wells is avoided. It provides the technical guarantee for the separate zone production of oil and water wells in offshore oilfields.

10.13639/j.odpt.2018.02.011