ExxonMobil confirms new Guyana discovery, assesses Ranger development

ExxonMobil (NYSE: XOM) has made a new hydrocarbon discovery at the Rockhead-1 exploration well in Guyana's offshore Stabroek Block, potentially strengthening the case for a commercial development centred on the nearby Ranger discovery.

Guyana's Minister of Natural Resources, Vickram Bharrat, confirmed the find to OilNOW, saying the US oil major would need to undertake further technical assessments to establish the size of the resource and determine whether additional appraisal drilling was necessary.

“[ExxonMobil Guyana] recently made the Rockhead-1 discovery in the Stabroek Block, adjacent to the Ranger-1 discovery. Ranger-1 is currently undergoing appraisal activities,” Bharrat said.

ExxonMobil has not disclosed estimates of recoverable resources at Rockhead or established whether the discovery is commercially viable.

“The quantification of the resources will be determined based on evaluated tests, and if necessary, an appraisal programme for the Rockhead-1 discovery,” Bharrat said.

The discovery forms part of ExxonMobil's wider exploration and appraisal programme in central Stabroek, where the company is investigating whether smaller accumulations could be connected to a future production hub at Ranger.

ExxonMobil vice president John Ardill said in a LinkedIn post that the company was gathering geological and reservoir data to assess development options around Ranger, which was discovered in 2018.

"This includes testing nearby prospects which could be tie-backs to a Ranger development. Rockhead is one of these near-field wildcat wells which was drilled earlier this year," Ardill wrote, according to OilNOW.

A subsea tie-back arrangement could allow hydrocarbons from neighbouring discoveries to be transported to shared production infrastructure, potentially reducing the investment needed to develop individual fields.

Ardill's comments followed a report by Energy Intelligence saying that an ExxonMobil executive had referred to a significant recent discovery in central Stabroek during the Energy Intelligence Forum 2026 in London. Appraisal work and production testing were under way to establish its scale.

It was not immediately clear whether the discovery mentioned at the forum was Rockhead.

The Stena Carron drillship was drilling Rockhead-1 in early August, approximately 213 km offshore Guyana, according to a maritime notice cited by OilNOW. Operations had been scheduled for completion by August 31.

ExxonMobil had identified oil as the exploration target but cautioned before drilling that the nature of any hydrocarbons encountered could not yet be determined with certainty.

The latest discovery adds to the exploration potential of the Stabroek Block, which has transformed Guyana into a major offshore oil producer since commercial production began in 2019.

ExxonMobil operates Stabroek with a 45% interest, alongside Chevron (NYSE: CVX), which holds 30% through Hess, and China's CNOOC (HKEX: 0883) with 25%.