MR 6C型钻井隔水管维修改造技术研究

某平台配置的MR 6C型钻井隔水管单根已服役多年,存在主管管体壁厚不足、隔水管单根间连接互换性差等问题,需进行维修升级改造。经检测评估,改造时重新利用了原有旧隔水管主管接头,切割更换了壁厚不足的主管管体。针对大直径异种壁厚的主管接头与主管管体间的组焊,制定了特殊的焊接工艺。以节流压井管线长度确定实际更换的每根主管管体长度,改造了10根老旧MR 6C型钻井隔水管单根。静水压试验表明维修改造后的MR 6C型隔水管单根满足高压密封和互换性等应用要求。

Repair Technology of MR 6C Marine Drilling Riser

One MR 6C drilling riser for a semi-submersible drilling platform have been used for many years and there are problems such as insufficient wall thickness of the main pipe body and poor connection interchangeability between the riser pipes. Maintenance and upgrade were required. After inspect and evaluation, the reconstruction reused the original old riser main pipe joint, and the main pipe body with insufficient wall thickness was cut and replaced. A special welding process has been developed for the group welding between large diameter heterogeneous wall thickness main pipe joints and main pipe bodies. The actual replaced length of every main pipe was determined by the length of choke & kills line. Hydrostatic test proved the repaired MR 6C drilling risers meet high pressure and interchangeability requirements.