Mooring System Integrity Challenges and Repair Experience of South China Sea Floating Production Units

Abstract This paper is written to provide working experience for mooring integrity works done in South China Sea. The relevant statistical data and repair methods of floater permanent mooring systems are to provide the industry with more references and insides. There are total 10 floating units operating in South China Sea (9 FPSOs and 1 FPS). Half of them were initially installed in mid to late 90's. The rest were put in production after year 2000. All FPSO moorings are permanent internal turret type. During the operation period, there have been various mooring system integrity issues. In the past 20 years, there have been 3 major mooring system incidents and other 5 with various integrity issues. For the total 8 cases, various mooing system remediation actions have been taken to bring them back to standard. Considerations for mooring system design, installation and inspection have been put in place for existing system continuous safe operation or new systems to be installed in this area. A mooring system integrity management system is also under development by CNOOC. This article tries to review all the mooring integrity issues we have faced in the past 20 years at South China Sea. The repair solutions for each case are briefed. Guide lines for improvements in design, installation and inspection for future systems are given. Mooring system integrity issues in South China Sea oil fields are related to areas of design, maintenance and inspection etc. The findings provide good information for new designs and help for better management of existing installations. It will also provide some shared learning on mooring system integrity management to other operators.