US independent Kosmos, having sold an operator’s stake to BP in 2016, is eying the $1bn sell-off of a further 20% in the 50-100tcf of gas it has discovered off Mauritania and Senegal. It claims 15tcf Tortue and follow-up projects as world-beaters on cost and timing. But scratch the surface and risks abound.

Texas-based E&P midcap Kosmos used its capital markets day on 25 February to set out its stall for the sale of a further 20% in the 10mn t/y Tortue FLNG development on the...