Chevron Corp. has prevailed in a 20-month fight to buy Hess Corp. for $53 billion, overcoming a challenge by arch rival Exxon Mobil Corp. that was unprecedented in the modern history of Big Oil.

The conclusion of the saga removes a stock overhang for Chevron and paves the way for the $53 billion deal to close immediately, which the oil giant said it could happen within a couple of days.

Chevron struck the deal to acquire Hess in October 2023. Exxon tried to block the move last year, saying it had a right of first refusal to buy Hess’ Guyana assets because of its joint operating agreement with Hess and the China National Offshore Oil Corp., or Cnooc, for the Stabroek Block.

The ICC ruled in favor of Chevron’s $53 billion acquisition of Hess, granting it a 30% stake in Guyana's Stabroek Block.

Chevron Corp. is on the cusp of reaching a production plateau in the largest US oil field, allowing it to reap billions of dollars of additional cash flow in the next few years.

Chevron’s imminent entry into Guyana’s rich offshore oilfields solves one of the biggest problems dogging the U.S. major: where its growth will come from beyond the next few years.