A major natural gas discovery offshore Mauritania may be the largest deepwater discovery this year and holds the potential for an export project, according to Kosmos Energy Ltd.

The Dallas-based operator said the Orca-1 exploration well hit gas in the BirAllah area, continuing a 100% success rate from nine wells targeting the inboard gas trend in Mauritania/Senegal. 

Partners in the BirAllah gas hub include operator BP plc, Kosmos, and Mauritania’s state-owned SMHPM.

“Orca-1, which we believe is the largest deepwater hydrocarbon discovery in the world so far this year, further demonstrates the world-scale quality of the Mauritania gas basin,” Kosmos CEO Andrew G. Inglis said. 

Orca-1 targeted a previously untested Albian play, exceeding pre-drill expectations and encountering 36 meters of net gas pay. In addition, the well extended the Cenomanian play fairway by confirming 11 meters of net gas pay near the original Marsouin-1 discovery well, which was drilled on the crest of the anticline, according to Kosmos.

Orca-1, around 7.5 kilometers (4.7 miles) from the crest of the anticline, “proved both the structural and stratigraphic trap of the Orca prospect, which we estimate has a mean gas initially in place (GIIP) of 13 Tcf,” management said.

“In total, we believe that Orca-1 and Marsouin-1 have de-risked up to 50 Tcf of GIIP from the Cenomanian and Albian plays in the BirAllah area, more than sufficient resource” to support a world-scale liquefied natural gas project. In addition, a deeper, untested Aptian play has also been identified within the area and surrounding structures.

Following the positive drilling result and because of the estimated scale and materiality of the Orca-1 discovery, Kosmos extended the timeline of its Mauritania/Senegal sell-down process into 2020, giving potential bidders additional time to analyze the data.

Located about 125 kilometers (78 miles) offshore Mauritania, the Orca-1 was drilled in 2,510 meters of water to a total measured depth of around 5,266 meters.

Orca-1 holds around 1.3 billion boe of recoverable resources, according to Rystad Energy’s Palzor Shenga, senior analyst on the upstream team. 

The offshore continues to dominate exploration in 2019, both in terms of the number of discoveries and the volume of resources unearthed, according to the analyst firm. With the latest discovery, Mauritania is tied with Guyana for the second most discovered volumes this year, trailing closely behind Russia with 1.5 billion boe. 

“This type of significant discovery, along with the projects lined up, could help establish the African nation as a major player and exporter in the industry,” Shenga said.

BP has successfully drilled the Tortue-1 and Ahmeyim-1 wells in the southern part of the area, while Bir Allah (former Marsouin-1) is in the northern part of the block.

BP and the partners in late 2018 sanctioned the initial phase of the Greater Tortue Ahmeyin development, designed to provide 2.5 million metric tons/year (mmty) of gas. The innovative cross-border export project is to produce from the deepwater development offshore West Africa beginning as soon as 2022.

Earlier this year, BP contracted TechnipFMC to build a floating production, storage and offloading unit (FPSO) to move forward with Phase 1. The initial subsea infrastructure is to connect the first four wells to the FPSO, where liquids would be removed. The gas would then be transported via pipeline to an LNG hub liquefaction terminal. 

Greater Tortue is to provide LNG for export, as well as for domestic use in Mauritania and Senegal. The start of gas production is expected in the first half of 2022. BP Gas Marketing already has agreed to buy LNG offtake from the first phase of the project.

The latest discovery in the Mauritania-Senegal-Gambia-Bissau-Conakry Basin has grabbed headlines recently because of discoveries in Senegal and Mauritania.

“Orca-1 not only targeted the untested Albian play, but has also identified a deeper Aptian play within the area,” according to Rystad. “The recent discovery is in line with BP’s strategy to build an additional LNG hub in the Bir Allah area.”

Mauritania and Senegal are becoming LNG centers, with three different planned hubs containing around 10 mmty, including the Yakaar-Terenga, Tortue and Bira Allah hubs.  

Rystad expects exports from the Greater Tortue project alone to increase to around 3 billion cubic meters (bcm) in 2026 from around 0.14 bcm in 2022.

Greater Tortue volumes “are not contracted, and therefore it is likely they will be included in BP’s export portfolio across the continent and made available for clients within the Atlantic basin,” Shenga said. “The inter-governmental agreement between the Senegalese and Mauritanian governments, combined with BP’s presence in all the three projects, offers a perfect synergy for future development and additional exports from these African countries.”