Exxon has joined BP and Total in bagging deepwater blocks offshore Mauritania, in the process adding to the chorus of majors plumping for deepwater as their next best non-Opec exploration hope after US shale.

Blocks C22, C17 and C14 are further offshore from blocks where BP and partner Kosmos have made a string of discoveries since 2015. BP plans a final investment decision by end-2018 on FLNG plans to develop the 15tcf Tortue field (MEES, 10 November).

Exxon’s new blocks total...