高温高压井双封隔器管柱安全评估

发布时间：2018-08-16 19:53

【摘要】：高温高压油气井投产后受到地层高温流体影响,完井管柱双封隔器密闭空间内的流体介质受热膨胀,导致圈闭憋压,可能造成油管挤溃和油层套管破坏的危险,严重威胁管柱服役周期和井筒完整性。针对密闭空间压力上升带来的安全生产问题,运用弹性力学和传热学理论,分析了温度载荷作用下井筒与地层耦合作用机理,研究了自由段油管和封固段油层套管处管柱位移形变量随温度和压力变化的关系,建立了双封隔器密闭环空压力预测模型,同时对不同生产工况下的封隔器管柱安全性能进行了校核分析。研究结果表明:在开井生产阶段,环空压力随双封隔器的间距增加而增加,不会影响管柱安全;在完井液循环阶段,考虑极端工况情况下,环空压力随双封隔器的间距增加而减小,但均超出油层套管抗内压强度,不能立即坐封,因此等待一段时间后坐封封隔器才能保证管柱的安全性能。
[Abstract]:When high temperature and high pressure oil and gas wells are put into production, they are affected by high temperature fluid in formation, and the fluid medium in the closed space of double Packer of completion string is heated and expanded, resulting in trap holding pressure, which may result in the collapse of tubing and the danger of casing failure in oil reservoir. A serious threat to string service cycle and wellbore integrity. Aiming at the problem of safety production caused by pressure rise in closed space, the coupling mechanism of wellbore and formation under temperature load is analyzed by means of elastic mechanics and heat transfer theory. In this paper, the relationship between temperature and pressure of displacement variables of tubing in free section and casing in sealing section is studied, and the pressure prediction model of double Packer closed annulus is established. At the same time, the safety performance of Packer string under different production conditions was checked and analyzed. The results show that the annular pressure increases with the increase of the distance between the two Packers and does not affect the safety of the pipe string in the open well production stage, and in the completion fluid cycle stage, the extreme conditions are considered. The annular pressure decreases with the increase of the spacing of the double Packer, but both of them exceed the internal pressure strength of the oil layer casing, so they can not sit down immediately, so the safety performance of the pipe string can be guaranteed by waiting for a period of time to sit the Packer.
【作者单位】：中国石油大学(北京)石油工程教育部重点实验室;中海石油(中国)有限公司湛江分公司;
【基金】：国家自然科学基金“海洋深水浅层钻井关键技术基础理论研究”(编号:51434009) 国家科技重大专项“浅层地质灾害识别与风险评价技术研究”(编号:2016ZX05033004-005) 国家自然科学创新研究群体项目“复杂油气井钻井与完井基础研究”(编号:51221003)
【分类号】：TE925.3

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