Novel installation methods and devices of steel catenary risers (SCR) in the South China Sea

The S-lay vessel cannot install steel catenary risers (SCRs) independently after it has finished the pipe-laying process as the stinger of the S-lay vessel is too long and the stinger undergoes a lot of pressure during the installation process. For extending the functions of the S-lay vessel, a special SCR installation system has been designed for the side of the vessel. It provides a solution for the S-lay vessel to install the SCR. Firstly, the SCR installation methods and related concepts are introduced, and the design method of an innovative SCR installation system is described in detail. In addition, a SCR installation method is proposed combining the actual situation of HYSY201 (S-lay vessel) and the environment of the South China Sea. An active truncated test method is taken to verify the security of the designed SCR installation system and the feasibility of proposed installation methods. The test results show that the SCR installation system performs well, and the suggested installation methods satisfy the requirements when using HYSY201 to install a SCR in the South China Sea. Finally, the multifunctional subsea structure installation system, which can be used to install, e.g. pipeline end termination (PLET), is introduced.