The SSIVs were located on the pontoon of SEMI, which shall be towed to site offshore by wet-tow method, and which case was the first-of-its-kind in China. the SSIVs shall moving up and down near the sea surface, so all the SSIV related facilities would be exposed to severe environmental conditions. This paper presents the system design of SSIV, the protection method and shows the analysis process against the challenge mentioned above. This can provide a good reference to the similar projects
Lingshui17-2 (hereinafter referred to as LS17-2) gas field is located in the northern part of the Qiongdongnan Basin in the western continental shelf of the northern South China Sea, with water depth of 1220m to 1560m. LS17-2 gas field is approximately 149km away from Sanya, Hainan Province, about 160km southeast from existing Yacheng 13-1 gas field, and about 90 km from gas export pipeline (YC13-1 to Hong Kong). The distance between LS17-2 gas field and the nearest onshore terminal (Nanshan terminal of YC13-1 gas field) is approximately 156km.
The development of LS17-2 gas field consists of subsea production system, one SEMI and subsea pipelines. The subsea production system comprises one west manifold and three east manifolds. The SEMI platform is located near Manifold EAST1. Well fluid from west production loop will be transported to LS17-2 SEMI for process through two 10" pipelines and two 10" SCR risers. Well fluid from all east manifolds will converge at Manifold EAST1 and then be transported to LS17-2 SEMI for process through two 12" SCR risers. After processing, qualified natural gas shall be pressurized and transported to subsea pipelines from YC13-1 platform to Hong Kong through a 18" subsea export pipeline. Condensate oil shall be sent to the storage tank on LS17-2 SEMI and be exported by DP Shuttle oil tanker.
