海洋弃井套管切割作业偏心工况分析

发布时间：2018-04-27 12:08

  本文选题：套管切割 + 偏心工况　； 参考：《中国海上油气》2017年02期

【摘要】：套管切割是海洋平台实施永久弃井时原井口装置切割回收的最关键环节,偏心工况切割套管时易形成不规则切口或导致套管未切断,造成刀片磨损严重、切割效率降低甚至导致井下事故。根据套管偏心切割受力模型,建立了切割面位置、割刀磨损长度及偏心切割扭矩的计算模型,并结合LH29-2-1井鐖339.725mm套管切割实例进行了计算分析,结果表明:割刀磨损长度随偏心距增大而增大;偏心工况时割刀切入套管各个方向的深度不一致,将导致套管切割作业失败;偏心切割工况时3个割刀切割总扭矩波动较大,随着切割的进行,单个割刀切割扭矩变化逐渐趋近正弦曲线波形,切割总扭矩波动幅度逐渐减小并最终趋于直线。上述认识可为判断套管切割工况及切割结果提供指导。
[Abstract]:Casing cutting is the most important link of cutting and recovering the original wellhead device when the offshore platform is permanently abandoned. When cutting casing in eccentric condition, it is easy to form an irregular cut or lead to casing not being cut off, resulting in serious wear of the blade. Cutting efficiency decreases and even leads to downhole accidents. According to the stress model of eccentric casing cutting, the calculation models of cutting surface position, cutter wear length and eccentric cutting torque are established, and the calculation and analysis are carried out with the example of 339.725mm casing cutting in LH29-2-1 well. The results show that the wear length of the cutter increases with the increase of eccentricity, the depth of cutting into the casing is not consistent under eccentric conditions, which will lead to the failure of casing cutting, and the total torque of the three cutters fluctuates greatly under eccentric cutting conditions. With the development of cutting, the variation of cutting torque of single cutter approaches to the waveform of sinusoidal curve gradually, and the fluctuation amplitude of total torque decreases gradually and tends to be straight eventually. The above knowledge can provide guidance for judging casing cutting condition and cutting result.
【作者单位】： 长江大学机械工程学院;长江大学油气钻完井工具研究中心;
【基金】：国家自然科学基金“深水无隔水管钻井涡动对钻柱动态响应研究(编号:51405032)” “十二五”国家科技重大专项“深水钻井装置安全作业与深水弃井工程应用技术及测试分析(编号:2011ZX05026-001-04-05)”部分研究成果
【分类号】：TE952
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本文编号：1810674