Chevron has secured its $53 billion acquisition of Hess, defeating Exxon in its yearslong attempt to block the deal and gaining control of an oilfield of major geopolitical importance.

The oil major announced on Friday that it completed the acquisition of Hess after an arbitration panel with the International Chamber of Commerce dismissed Exxon’s claim that it had the right to preempt the bid for Hess’s coveted assets in the offshore Guyana oilfields.