Chevron won its hotly contested legal battle against rival Exxon Mobil, allowing it to immediately close its $53 billion acquisition of Hess on July 18 and give the Big Oil major access to arguably the biggest oil discovery of the century offshore of sparsely populated Guyana.

Longtime shale boss and North Texas energy magnate Scott Sheffield said he’s no longer interested in joining Exxon Mobil Corp.’s board after the U.S.

Former Pioneer Natural Resources CEO Scott Sheffield told Hart Energy, “For now, I remain one of Exxon’s largest individual shareholders and as such will consider other options.”

Chevron has prevailed against Exxon Mobil in a dispute over Hess Corporation’s offshore oil assets in the South American nation of Guyana.

The FTC has reopened an order involving Chevron’s proposed acquisition of Hess, and another regarding Exxon Mobil’s proposed purchase of Pioneer Natural Resources after its initial complaints failed to plead any antitrust law violation.