Project Profile

Location: Mauritania and Senegal boundary
Capacity: 4 million tonnes per year
Tortue Reserves: 15 tcf (425 bcm)
Start-up year:  2021 (Train 1), 2023 (Train 2)

The Greater Tortue Ahmeyim (GTA) field offshore Mauritania and Senegal is a large, deep-water gas complex with two main reservoir sequences, the Lower Cenomanian and the Albian. The area was discovered by Kosmos Energy (Kosmos) in April 2015 by the Tortue-1 discovery well. Kosmos has since successfully confirmed three major fairways of the Senegal River Trend within the broader Mauritania and Senegal basin with the Guembeul-1A, Marsouin-1, Ahmeyim-2, Teranga-1, and Yakaar-1 wells. The outboard Cretaceous petroleum system offshore Mauritania and Senegal is potentially one of the largest petroleum systems ever opened along the Atlantic Margin.

Kosmos entered into a joint venture partnership with BP in respect of its interests in Mauritania and Senegal in December 2016. Dynamic production data was desired to further appraise the Lower Cenomanian reservoirs. A fast-track Drill Stem Test (DST) was conceived, planned, and conducted on the Tortue-1 discovery well beginning in June 2017 to assist in validating reservoir connectivity, productivity, original gas-in-place, and fluid quality. The DST, operated by Kosmos on behalf of the partnership, targeted two distinct reservoirs within the Lower Cenomanian sequence. The key information extracted from the well test has been used to support the Front End Engineering Design (FEED) currently underway, with a corresponding Final Investment Decision (FID) planned in late 2018.

Tortue West Gas Field

Tortue-1 was drilled in mid-2015. The exploration well, later given the name Ahmeyim, encountered approximately 117 meters of net hydrocarbon pay in high-quality reservoir sands in the Cenomanian and Albian intervals.

Ahmeyim-2 well was later drilled and confirmed lateral reservoir continuity extending the  field area to 90 square kilometres. The well encountered 78 meters of net gas pay in two excellent quality reservoirs, including 46 meters in the Lower Cenomanian and 32 meters  in the underlying Albian.


Operators:

BP

Kosmos Energy


Contracts:

CH2M: Marine engineering support contract

KBR: Pre-front end engineering design (FEED) and project support services.

McDermott：substantial engineering, procurement, construction and installation (EPCI) SURF contract.

BHGE：Five large-bore deepwater horizontal xmas trees (DHXTs)，A six-slot dual bore manifold，A pipeline end manifold，Subsea distribution units (SDUs)，Three subsea isolation valves (SSIVs)，Diverless connections，Subsea production control systems