Field Development Overview of Liuhua 11-1 and Liuhua 4-1 Oil Field

Abstract The Liuhua 11–1 oil field, to date, the largest oil field in the South China Sea, is located in approximately 310 meter of water. It was the first deepwater field in the South China Sea originally developed by a consortium of Amoco, CNOOC and Kerr-McGee in 1995. The development includes a Floating Production System (FPS) with a subsea production system, and a Floating Production Storage Offloading (FPSO) located approximately 3km northwest of the FPS. The development of a nearby field, the Liuhua 4–1, about 11km away from Liuhua 11–1, was approved in early 2010 and produced in 2012 through the Liuhua 11–1 FPS facilities via subsea tieback, which requires to FPS life extension and topsides capacities upgrading for another 15 years. There are significant technical challenges for the life extension and dry dock upgrade of the FPS, as well as the subsea tie-back of the Liuhua 4–1 field. The FPS mooring and subsea control risers need to be disconnected and reconnected after the FPS drydock. The new 11km subsea pipeline between two oil fileds, control umbilical and electrical cable risers need to be installed. The FPS upgrade project started in 2010 and completed successfully in 2012 with the reconnection of the mooring and risers to the FPS. Both the Liuhua 11–1 and the Liuhua 4–1 fields are currently producing. This paper gives an overview of the Liuhua11–1 and Li uhua4–1 development as a case study for South China Sea deepwater development and also discusses the technology and project execution for developing nearby marginal fields. Introduction Liuhua 11–1 Oil Field is the deepest oil field on production in China to date, located in South China Sea, started first oil production on March 1996. She was called a " crown jewels" in offshore oil industry with a series of technical innovation at that time, and she is still on production after 17 years service. Liuhua 4-1, as a marginal oil field, was developed via tie back to the Liuhua 11–1 Oil Field, raised new requirement on the existing offshore facilities. China National Offshore Oil Corporation (CNOOC) faced serious challenges on facilities upgrade, FPS disconnection, re-hookup, and technicalogy and project management. The Semi-Submersible Platform FPS Nan " Hai Tiao Zhan" was disconnected on Oct. 2011, went to Dry Dock upgrading, re-hookup on location on May 2012. Liuhua 11–1 production resumed on June and Liuhua 4–1 started the First Oil on July and all 8 wells were on production in Sept. 2012.