Plans to utilise a floating LNG production (FLNG) vessel to develop the Tortue/Ahmeyim field in an area that straddles the territorial waters of Senegal and Mauritania are moving ahead rapidly only 16 months after the discovery of the gas deposit.
The partners in the Greater Tortue FLNG project are targeting a final investment decision by the end of 2018. BP, leading the venture, stated that the field contains 15 trillion cubic feet (tcf) of recoverable gas, equivalent to 300M tonnes of LNG.
The scheme calls for gas from four separate wells to be processed by an oil floating production storage and offloading vessel to remove liquids from the stream. The dry gas would then be piped 100 km to a nearshore FLNG vessel for liquefaction and transfer to loading LNG carriers.
A number of engineering firms have been signed up to carry our front-end engineering and design (FEED) studies for various parts of the project. Among the challenges facing the developers of Greater Tortue are waters depths of up to 2,700 m.
Golar LNG has won the contract to carry out the FEED work on the FLNG vessel, and the intention is to convert one of the company’s LNG carriers for use as a floating LNG producer. A preliminary charter agreement has already been signed.
Golar has earmarked three of its older, 125,000 m3 spherical tank LNGCs for such conversion work. The reconfiguration of Hilli has already been completed at the Keppel yard in Singapore and the vessel is currently commencing operations on the Kribi field off the coast of Cameroon as Hilli Episeyo in what is the world’s first LNG export project utilising a converted FLNG vessel.
A second LNGC, Gandria, is lined up to provide a similar role for the Fortuna project in waters off the coast of Equatorial Guinea. Ophir Energy, the operator of the Fortuna initiative, is seeking to finalise the financing of scheme in the months ahead and Gandria is currently lined up at Keppel for early conversion work to commence.
Golar’s third FLNG conversion candidate is Gimi, built, like Hilli, in Norway in the mid-1970s.
The Greater Tortue FLNG vessel will be positioned at a jetty location close to shore near the Senegal-Mauritania border. The jetty would be protected by a breakwater and the preliminary charter agreement includes an option for a second project FLNG vessel. Some gas would also be available for the domestic market.
An FID on the project by the end of this year would enable the FLNG vessel to begin producing cargoes for export by the end of 2021.