US supermajor ExxonMobil and Norwegian oil giant Equinor have quit plans to participate in the potential development of a new natural gas cluster offshore Brazil, leaving state-controlled company Petrobras to decide whether or not it will proceed alone.

In a one-year period from mid-2020 to mid-2021, Petrobras drilled a quartet of high-profile exploration wells in the pre-salt fairway in the relatively unexplored ultra-deepwater section of the prolific Campos basin.

The ambitious campaign resulted in three discoveries — Naru in Block C-M-657, Urissane in Block C-M-411 and Mairare in Block C-M-346 — while Yba in Block C-M-709 was apparently a dry hole.