Xijiang 30-2 and 24-3 Caisson Guide Failure Analysis and Repair (1998)

Xijiang 30-2 and 24-3 Caisson Guide Failure Analysis and Repair Roger L. Thomas; Roger L. Thomas Phillips Petroleum Company Search for other works by this author on: This Site Google Scholar Anthony Tai; Anthony Tai Phillips China Inc. Search for other works by this author on: This Site Google Scholar R.W. Litton; R.W. Litton Bechtel Offshore Search for other works by this author on: This Site Google Scholar James Rodgers; James Rodgers Phillips China Inc. Search for other works by this author on: This Site Google Scholar Rico Huang Rico Huang China Offshore Oil Nanhai East Corporation Search for other works by this author on: This Site Google Scholar Paper presented at the SPE International Oil and Gas Conference and Exhibition in China, Beijing, China, November 1998. Paper Number: SPE-48866-MS https://doi.org/10.2118/48866-MS Published: November 02 1998 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Thomas, Roger L., Tai, Anthony, Litton, R.W., Rodgers, James, and Rico Huang. "Xijiang 30-2 and 24-3 Caisson Guide Failure Analysis and Repair." Paper presented at the SPE International Oil and Gas Conference and Exhibition in China, Beijing, China, November 1998. doi: https://doi.org/10.2118/48866-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE International Oil and Gas Conference and Exhibition in China Search Advanced Search AbstractOn December 6, 1996, two seawater lift guides (one at the +19 foot level and one at the -40 foot level on the same caisson) and one firewater caisson guide (at -40 foot level) on the Xijiang 30-2 (XJ30-2) platform offshore South China Sea failed at the connection between the guide bucket and the standoff brace. The failed guides were missing and later retrieved from the seabed. Subsequent inspection detected cracks in other guides supporting the 24-inch caissons on both the XJ30-2 and Xijiang 24–3 (XJ24-3) platforms. Five temporary clamps (two firewater and two seawater on XJ30-2, and one firewater on XJ24-3) were installed to support the caissons at the -40 foot level to allow production to continue during the winter months. Analyses were undertaken to determine the cause of the failures and design of the final repair/strengthening to support the remaining caissons.Analyses showed that the fatigue failure occurred due to dynamic loading caused by movement of the caissons inside the guides. Initially, wet welding permanent support members at the -40 foot level for the caissons was considered, but detailed FEA analyses of the proposed wet welded doubler plates showed high stresses in the wet welds that could cause future fatigue problems. Permanently installed clamps were designed and installed on all 24-inch caissons at the -40 foot level to replace the original guides. The + 19 guides were also replaced by welding supports between the structure and the caissons. This paper will cover the conclusions drawn from the analyses of the failure, analysis of proposed repair options, the decision making process that led to the final repair solution, and the fabrication and installation of the repairs.P. 361 Keywords: wave height, temporary clamp, vertical shell, stub, floating production system, upstream oil & gas, caisson, fpso, conductor, installation Subjects: Offshore Facilities and Subsea Systems, Floating production systems This content is only available via PDF. 1998. Society of Petroleum Engineers You can access this article if you purchase or spend a download.