Greater Tortue Ahmeyim is an offshore liquefied natural gas (LNG) project based on upstream gas production in 2km-deep waters on the maritime border of Mauritania and Senegal. It is the deepest offshore project in Africa till date.
The LNG project is being jointly developed by BP, Kosmos Energy, Societe des Petroles du Senegal (Petrosen), and Societe Mauritanienne des Hydrocarbures (SMHPM) with BP as the operator.
Planned to be developed in phases, the Greater Tortue Ahmeyim LNG project will produce up to 10 million tonnes of LNG a year (Mtpa).
The project will produce 2.5Mtpa of LNG in its first phase of development for which the final investment decision (FID) was taken in December 2018.
Construction on the offshore LNG project is expected to be started in the first half of 2019, with the start of commercial production is scheduled for 2022.
Greater Tortue Ahmeyim discovery and development history
The Greater Tortue Ahmeyim project is based on the development of two offshore gas fields namely Tortue and Ahmeyim.
The Tortue field, located in the C-8 block in Mauritania offshore waters, was discovered by the Tortue 1 discovery well, which was drilled up to a depth of 2.7km in 2015.
The Ahmeyim field, located in Saint Louis Offshore Profond block of Senegal, was discovered by the Ahmeyim-2 discovery well, which was drilled up to 5.2km depth in 2016.
The Tortue 1 discovery well encountered 117m of net gas pay, while the Ahmeyim-2 encountered 78m of net gas pay.
BP entered into an agreement with Kosmos Energy for co-developing the gas fields in December 2016.
The governments of Mauritania and Senegal signed an inter-government co-operation agreement to develop the cross-border Greater Tortue Ahmeyim offshore gas field in February 2018.
Greater Tortue Ahmeyim ownership details
The Saint-Louis Offshore Profond block offshore Senegal is owned by BP (60%), Kosmos Energy (30%), and Petronas (10%).
The C-8 block offshore Mauritania is owned by BP (62%), Kosmos Energy (28%), and SMHPM (10%).
Greater Tortue Ahmeyim gas reserves
Spread over 33,000km², the Greater Tortue Ahmeyim field is estimated to contain approximately 15 trillion cubic feet (tcf) of recoverable gas reserves.
Infrastructure facilities for Greater Tortue Ahmeyim phase one development
The Greater Tortue Ahmeyim field will be initially developed with a deepwater subsea production system comprising four gas production wells tied-back to a floating production, storage and offloading (FPSO) unit.
The gas will be processed for the removal of heavier hydrocarbon components on the FPSO. The processed gas will be further sent via a 100km-subsea pipeline to a near-shore floating LNG (FLNG) facility.
The FLNG will be capable of producing 2.5Mtpa of LNG a year for global export. The remaining gas will be sent through pipelines to Mauritania and Senegal gas markets, for domestic consumption.
BP Gas Marketing will off-take the entire LNG output from the Greater Tortue Ahmeyim phase one development project.
Contractors involved with Greater Tortue Ahmeyim
KBR was awarded the front-end engineering and design (FEED) contract for the near-shore LNG terminal for the Greater Tortue Ahmeyim project, in October 2018.
KBR was also awarded the pre-FEED contract along with project support contract for the offshore LNG project in August 2017.
CH2M HILL was sub-contracted by KBR for the civil and marine engineering services of the Greater Tortue Ahmeyim LNG project in October 2017.
TechnipFMC was awarded the FEED contract for the FPSO unit of the Greater Tortue Ahmeyim LNG project in April 2018.
A joint-venture between McDermott International, and Baker Hughes (BHGE) was awarded the FEED contract the subsea systems including umbilicals, flowlines, and risers (McDermott) and subsea production system (BHGE), in March 2018.