HOUSTON—Until recently, successful E&P work offshore Mauritania and Senegal has lagged. Today, however, BP Plc (NYSE: BP) and Kosmos Energy Ltd. are working together to develop resources in the region, including the deepwater Tortue Field estimated to hold more than 15 trillion cubic feet (Tcf) of gas.

Work over the past 60 years, pointing to “proof of source rock, reservoirs and fairways and a range of trap types,” finally led to commercial discoveries in the past two years and sparked excitement, according to Kosmos CEO Andrew Inglis.

At an industry breakfast at OTC 2017, he said half a billion dollars has already been invested and that Kosmos is ready to continue its work in the region. The frontier pioneer “saw a region that was underexplored, where we could use our deep technical capability to open up a new basin,” Inglis said.

Kosmos and BP are working with both governments as the companies move toward first gas production by 2021 with the Tortue project, Inglis said, adding the governments see long-term benefits. The countries, both considered resource-rich but impoverished, could become LNG exporters. The billions in revenue could support “other sectors such as health, education and infrastructure” and create jobs, Inglis said, making the area more attractive to the oil and gas industry.

Related: Kosmos Strikes Gas Offshore Mauritania, To Pursue LNG Project

Until 2012, when Kosmos acquired three blocks in an area called Tortue on the two countries’ maritime border, several operators and partner groups drilled about 200 wells over 60 years with little success. This made the greater Mauritania-Senegal area seem too high-risk and untenable, Inglis said.

Since then, much has happened with natural gas.

BP is the operator of the Tortue project. BP entered the project with a 62% working interest, including operatorship, of Kosmos’ Mauritania blocks, and a 32.49% effective working interest in Kosmos’ Senegal blocks, according to a BP press release from December 2016.

Follow The River

Inglis said that Kosmos’ geologists studied results of the many previous wells and devised a new theory about Mauritania’s hydrocarbon potential. In the Cretaceous period, the Senegal River Delta and Mauritania’s Nouadhibou River Delta pushed reservoir sands beyond the continental shelf. Inglis said the shelf “had been the focus of the failed exploration to date.”

The river systems in the Cretaceous pushed the sands into deeper water. “We also hypothesized there was a deeper source rock working in the basin.” Based on this concept, Kosmos acquired three blocks in 2012, and 3-D seismic data indicated there was “an especially large and promising geologic structure that appeared to extend across the maritime boundary of Mauritania and Senegal,” Inglis said.

In 2014 Kosmos acquired two Senegal blocks “adjacent to and on-trend with the Mauritania blocks. Once acquired, they enabled an integrated approach to the exploration of the deep part of the Senegal River Basin, and we saw the tremendous potential. Our contrarian idea turned out to be correct,” he said.


According to Kosmos’ website, Tortue-1, or Ahmeyim, was drilled in mid-2015 and hit about 117 m (373 ft) of net hydrocarbons in high-quality reservoir sands. Guembeul-1 was completed in 2016 and encountered 101 m (331 ft) of net gas pay in two reservoirs, including 56 m (184 ft) in one formation and 45 m (148 ft) in another.

Ahmeyim-2 was drilled, encountering 78 m (256 ft) of net gas pay in two reservoirs. Inglis stressed the great potential of this area. “This is one of the big messages I want to leave with you today: this is a world-scale basin.”

He said a gross resource of about 25 Tcf “along a fairway stretching 80 km north and 80 km south of the Mauritania-Senegal maritime boundary, shared equally between the two countries,” was found. “We’ve also de-risked an additional 25 Tcf of potential in the basin as a result of that work.”

There’s a plan for all that gas.

Unmet Potential

The economic benefits of Mauritania’s hydrocarbon resources will be realized slowly, said Mohamed Abdel Vetah, the country’s minister of petroleum, energy and mines.

The World Food Program estimated that 47% of Mauritania’s population of 4 million is impoverished, and the nation suffers from “the resource curse”—low GDP while resource-rich.

Currently, progress in the mining sector lags, as it does in other sectors, due to the country’s lack of energy infrastructure, Abdel Vetah said.

Power generation is the first priority for the country, he said, and cheap gas will be the key. Developing power infrastructure with gas would jumpstart mining in north Mauritania, he added.

This gas will be extracted from Greater Tortue using subsea wells, and sent to treatment facilities, then FLNG modules and storage offtakes. Most of the gas will be exported, with revenue benefiting both Mauritania and Senegal.

Abdel Vetah said the initial domestic gas demand is not huge.

The CIA World Factbook reported that  Senegal consumed 46 million cubic meters of natural gas on a 2014 estimate. This amount is the same it was reported to produce.

After a final investment decision is reached next year, first gas from the Tortue project is expected by 2021, according to Bernard Looney, CEO of upstream for BP.

“Gas is set to be the world’s most important fuel for the next couple of decades,” Looney said while discussing the need to close the gap between worldwide energy demand and supply. By 2025, global demand for energy will have grown 30%. There are more than 50 years’ worth of proved oil and gas reserves worldwide, he said, adding that the most competitively priced resources will help meet this demand.

Looney also noted that the Mauritania-Senegal effort bolsters BP’s effort to shift toward gas, making it 60% of its production by the mid-2020s compared with today’s roughly 50%.

“We choose our investments very carefully,” he said, including “our newest investment that we’re discussing here today, in Mauritania and Senegal. The common factor is that the projects are large-scale, long-term and highly competitive.”

Looney said that the total acreage of the deepwater Tortue Field, which is 33,000 sq km, could contain 50 additional Tcf.  

Looney outlined plans for Tortue:

  • The exploration program will have four wells drilled over 12 to 18 months, with further work planned;
  • The field will be developed in phases and come onstream in 2021; and
  • Developers will also work with Mauritania and Senegal’s governments so resources benefit the people.

Inglis said the first FLNG vessel will have capacity for 2.5 million tonnes per annum (mtpa), while the second could hold up to 5 mtpa. He cautioned that all of this will be off to a slow start, noting LNG projects as a trend might start smaller because LNG markets are becoming more diversified.

Although Senegal and Mauritania have different fiscal regimes, Abdel Vetah said the governments, BP and Kosmos have aligned on nearly all aspects of the work agreement.

Regarding a news report May 2 that Senegal’s President Macky Sall dismissed the energy minister, Thierno Alassane Sall, a longtime collaborator who is no relation, Inglis said he could not speculate whether the report was accurate.

Related: Anxiety Brews Over Government's Role In Senegal's Looming Oil Boom

Related: Report: Senegal's President Dismisses Energy Minister

However, Inglis said the industry must lead by example on this project as it works with both countries’ local content requirements and laws. “Get it right from Day One,” he emphasized, adding, “this is not a problem; this is an opportunity.”

Erin Pedigo can be reached at epedigo@hartenergy.com.