连续管对口焊接技术及现场应用

连续管焊接接头不仅要求具有较高的强度,而且必须有好的塑性和耐蚀性。在介绍连续管焊接方法、焊接设备及焊接程序的基础上,对连续管对口焊接关键点进行了分析,包括焊条匹配选择、焊缝与连续管本体强度匹配控制、焊接成型控制和焊口与管体综合性能一致性控制。结合LN201井失效落井的50.8 mm连续管,采用焊条低组配、窄对口、小间隙及钨极氩弧焊接工艺实施焊接,并对形成的焊缝进行了探伤检测、弯曲检测和挂重拉力检测。探伤显示焊缝无弧坑、无表面气孔和电弧擦伤;弯曲检验显示焊缝2次通过注入头、鹅颈管,无异常现象。

Joint Weld Technology for CT and Field Application

Both high strength and good plasticity and corrosion resistance are required for the welded joint of coiled tubing(CT).On the basis of an introduction of CT welding method,welding equipment and welding procedure,an analysis of the key point of CT joint weld was conducted,including such aspects as electrode matching selection,strength matching control of weld seam and CT body,weld forming control and performance consistency control of weld junction and CT body.Referring to the 50.8 mm CT broken down in Well LN201,the under-matched electrode,narrow joint,small crack and inert gas arc were adopted to conduct welding.An defect inspection and bending and pulling tests of the weld seam were performed.The defect inspection shows that the seam has neither crater nor surface stomata nor arc abrasion.The bending test shows that the seam remains normal while going through the injector head and gooseneck twice.