井下管柱熔融切割工具研制

Development of Downhole String Melting Cutting Tool

现阶段井下管柱恶性遇卡处置效率低、处置时间长,甚至会诱发井眼附加伤害,成为制约井下作业效率及安全的主要因素。为此,研制出一种基于高温熔融的金属管柱快速切割解卡作业工具。将工具下放至目标深度后,利用锚定机构实现工具与被切割管柱的相对固定,采用电激发特制的高能铝热药柱;铝热药剂急速反应释放极量、超高温的等离子火焰;火焰由特殊设计的喷射机构引导喷射,沿径向高速喷出对管柱实施径向熔切。开展液态环境中ø127 mm加重钻杆熔切试验,验证工具井下作业的可行性。研究结果表明:锚定机构能顺利完成工具与被切割管柱的相对固定,药剂能被顺利激发,喷射机构能引导火焰高速喷射实施径向熔切。该工具可对不同厚度的管柱实施熔切作业,管柱熔切深度与装药量相关,10 kg装药量下,切割用时8 s,切割平均深度达21 mm。该工具及其技术可为井下遇卡管柱高效、安全解卡提供新的解决方案。

Currently,the disposal of malignant downhole stuck string is inefficient and time-consuming,which may cause additional damage to the wellbore and has become the main factor restricting the efficiency and safety of downhole operations.Therefore,a rapid cutting unfreezing tool for metal string based on high-temperature melting was developed.After the tool was lowered to the target depth,an anchoring mechanism was used to achieve a relative fixation of the tool and the cut strings,and the electricity was use to excite the purpose-made high-energy thermite grain.The thermite rapidly reacted and released a large amount of ultra-high temperature plasma flame.The flame was ejected radially at high speed under the guidance of a specially designed jet mechanism and imple-mented radial melting cutting on the string.Moreover,a melting cutting test ofø127 mm heavy wall drill pipe was carried out in a liquid environment to verify the feasibility of downhole operation of the tool.The research results show that the anchoring mechanism can successfully complete the relative fixation of the tool and the cut strings,the thermite can be successfully excited,and the jet mechanism can guide the flame to eject at high speed and imple-ment radial melting cutting.The melting cutting depth of the strings are related to the thermite load,and the tool can perform melting cutting operation on different thickness of strings.At a thermite load of 10 kg,the average cut-ting depth reaches 21 mm after 8 s of cutting.The tool and its technology provide a new solution for efficient and safe unfreezing of downhole stuck strings.