摘要
油田上经常发生油管破断等事故,最常见的原因是管柱发生破损,严重影响油田正常生产。为了探索油管破断的原因,需根据井下实际情况,对油管破坏原因进行试验验证。以钢级P110S,规格为Φ88.9 mm×6.45 mm的油管为例,介绍了未受破坏的油管拉伸至失效和有管钳咬痕油管拉伸至失效的试验,对比两种不同情况对油管强度影响的大小,认为受管钳破坏的油管强度在其破坏处影响最大,确定了应力集中发生位置和应力集中系数大小。对有管钳咬痕油管进行有限元数值模拟,结果表明在咬痕处发生应力集中现象,且变形量最大值也发生在油管咬痕位置。利用有限元模拟了不同咬痕长度、宽度、深度对油管强度的影响,其中咬痕长度对其影响最大。其为寻找油管在井下发生破坏的原因提供了思路和方法,对井完整性保护具有重要的意义。
Tubing breakage accidents often occur in oilfields. The most common reason is the damage of the tubing string, which seriously affects the normal production of oilfields. In order to explore the cause of tubing breakage, the test of tubingis necessary according to the actual situation of the well. In this paper, taking the tubing with the grade P110 S and the specification of Φ88.9×6.45 mm as an example, the tensile tests of the complete tubing and the tubing with pipe wrench bite were carried out. The results show that the pipe wrench bite has a great influence on the tensile strength of tubing. The stress concentration location and the stress concentration coefficient of the tubing with pipe wrench bite are determined. The numerical simulation result of the tubing with pipe wrench bite shows that the stress concentration occurs at the bite mark, and the maximum deformation occurs at the bite mark. The influences of bite length,width and depth on tubing strength are simulated by finite element method, and the results show that the bite length has the greatest influence on tubing strength. The research result in this paper provides ideas and methods for finding out the causes of tubing damage in downhole, and has important significance for well integrity protection.
引文
[1]窦益华,许爱荣,张福祥,等.高温高压深井试油完井问题综述[J].石油机械,2008,36(9):140-142.
[2]贾宗文,刘书杰,耿亚楠,等.弯曲井段套管抗挤强度理论及试验研究[J].石油机械,2018,46(9):100-105.
[3]邱亚玲,詹大年,颜凌宇.偏磨油管失效判据的有限元分析[J].石油矿场机械,2016,45(4):24-27.
[4]王学岐,樊建春,张来斌.偏磨油管剩余强度有限元分析[J].润滑与密封,2008,33(12):47-48,51
[5]朱加强,宁明,袁金雷,等.含圆锥形腐蚀坑油管的剩余强度研究[J].钢管,2016,45(3):62-67.
[6]李霄,温庆伦.含腐蚀坑连续油管极限腐蚀坑深度及剩余强度评估[J].石油矿场机械,2016,45(4):5-7.
[7]王军,王红江,姬丙寅,等.含典型腐蚀缺陷油管的剩余抗拉强度研究[J].钢管,2017,46(4):15-22.
[8]聂尊浩,黄宇,文冉.ANSYS软件在油管强度分析和校核中的应用[J].石化技术,2017,24(10):46-48.
[9]杨竞哲.油管断裂失效的分析[D].长春:吉林大学,2010.