应用水下常压干式舱修复导管架裂纹

Application of Underwater Atmospheric Pressure Dry Cofferdam in Jacket Cracks Repair

要彻底修复导管架裂纹,采用水下常压干式舱进行焊接修复是最好的办法。结合成功地采用水下常压干式舱,对在中国南海LF7-2导管架主桩腿上检测发现的多条贯穿性裂纹进行焊接修复的案例,介绍了导管架模拟节点的建造、采用逆向工艺建造整体舱体、法兰螺栓的安装和拆卸、安全岛的建造等关于水下常压干式舱建造的内容;论述了临时平台和绞车的作用、临时管卡的安装、干式舱和导管架之间间隙的调整、楔形密封件的安装、水下干式舱的查漏封堵、干式舱内部构件的安装等涉及水下常压干式舱海上安装的内容,以及干式舱的应用经验。

Using the underwater atmospheric pressure dry cofferdam is the best approach to completely repair the cracks of jacket. Multiple penetrative cracks were found in the main legs of LF7-2 jacket in the South China Sea, and then were repaired by this approach. In this paper, the construction of the underwater atmospheric pressure dry cofferdam is described, involving the simulated jacket node structure, cofferdam body construction by inverse procedure, flange bolts installation and disassembly, security island construction. Also, the marine installation of the cofferdam is described, involving the function of temporary work platform and winch, temporary pipe clamp installation, adjustment of the gap between the cofferdam and the jacket, wedge shaped seal installation, cofferdam leakage inspection and sealing and cofferdam internal parts installation. In addition, the experience of applying the cofferdam is presented.