World's first newbuild LPG FPSO planned for operation off Angola

Cabinda Gulf Oil Co. Ltd has arranged for the world's first newbuild liquefied petroleum gas (LPG) FPSO, which is slated for operation in Sanha field on Block O, off Angola.

By OGJ editors

HOUSTON, Oct. 16 -- Cabinda Gulf Oil Co. Ltd., a wholly owned subsidiary of Chevron Texaco Corp., has arranged for the world's first newbuild liquefied petroleum gas (LPG) floating production, storage, and offloading vessel, which is slated for operation in Sanha field on Block O, off Angola.

Cabinda—operator of Sanha field, with a 39.2% interest—signed a contract last spring with Single Buoy Moorings Inc. (SBM) of Monaco for an 8-year-lease time charter of an LPG FPSO unit for Sanha to be built and owned by Sonasing, a joint venture of SBM and Angola's state oil company Sonangol EP (Sociedade Nacional de Combustiveis de Angola), which is a 41% interest holder in Sanha field. Other stakeholders include TotalFinaElf SA 10%, and ENI SPA's Agip Petroleum Co.9.8%.

Mitsui & Co. Ltd. and Ishikawajima-Harima Heavy Industries Co. Ltd. (IHI), Tokyo, have signed a construction contract with SBM to build the Sanha LPG FPSO. The unit is slated for completion in mid-2004, with the first product expected to be shipped in 2005.

With an LPG storage capacity of 135,000 cu m and a daily processing capacity of 6,000 cu m, the Sanha LPG FPSO will be the largest LPG hull ever built and the first floating production facility built to combine all LPG processing and export functions onboard the same unit. The LPG production plants will include gas separators, gas refrigerators, and boil-off gas reliquefaction units.

Mixed LPG, received from two LPG production platforms in Block O, will be fractionated onboard the FPSO to separate butane and propane products. Each product will then be chilled for storage in atmospheric pressure storage tanks and periodically transferred to LPG export tankers for shipment and sale.

ABS Corp., Houston, will provide classification services. ABS said it is the only classification society to have experience with the type of liquid gas containment systems being used for the Sanha. The vessel will use IHI's self-supporting, primatic-shape, IMO Type-B tank system.

Previously, ABS had classed the only LNG carriers to use this containment system and also classed the first LPG FSO newbuild, the Escravos, which is fitted with the same type of tanks. The Escravos is in service for ChevronTexaco off Nigeria (OGJ, June 24, 2002, p. 58).

The Sanha project will greatly reduce the amount of gas flaring on Block O, project participants said. "Demand for LPG FPSOs is being driven by environmental concerns that have placed severe restrictions on the traditional method of flaring gas associated with production," said William J. Sember, ABS vice-president, offshore project development. "By capturing these gases, not only does the environment benefit but also, with the demand for gas forecast to double over the next decade, industry and consumers will benefit from this new technology."

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