Oil and gas plays opened in recent years are not expanding along the same trajectory as major earlier successes that included Guyana, according to Westwood Global Energy Group.
Jamie Collard, Westwood’s Senior Exploration Research Manager, made the assessment during a mid-year webinar examining global exploration performance in the first half of 2026 and the outlook for the remainder of the year.
“We had been seeing some pretty large plays open prior to 2015, such as in Guyana, the Nile Delta… and Alaska,” Collard said. “Then we had a few pretty quiet years.”
Guyana’s offshore oil success began with the Liza-1 discovery in the Stabroek Block in May 2015. Production started in December 2019, less than five years later. The ExxonMobil-operated block has since supported four producing developments, with output averaging more than 900,000 barrels per day in early 2026. ExxonMobil last publicly placed the block’s discovered resource at nearly 11 billion oil-equivalent barrels.
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Westwood reviewed 38 new plays opened since 2011. Only eight had grown to contain more than one billion barrels of oil equivalent in commercial resources. Collard said the newer plays appear smaller than those opened during the earlier part of the period.
“Maybe what’s more worrying is that the plays opened in recent years do appear to be smaller in scale,” he said.
About half of the 38 plays contained oil, while a similar share contained gas. Four contained a mixture of hydrocarbons, he shared. Westwood also examined the pace at which resources accumulated as drilling continued in each play.
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Westwood classifies a play as frontier before its first commercial discovery. It becomes emerging as discoveries accumulate rapidly, then moves into the maturing and mature stages as the rate of resource additions slows. The Orange Basin has also attracted significant exploration activity following discoveries in its Upper and Lower Cretaceous plays.
“There’s plenty more wells planned in both the Lower and Upper Cretaceous plays in the Orange Basin, but even here, we’re just not seeing the plays emerge on the same trajectory that some of the giant plays earlier in the period achieved,” Collard said.
Westwood found that about one in 10 frontier wells leads to a commercial discovery. When combined with the limited number of plays that grow beyond one billion barrels of oil equivalent, the probability of a frontier well opening a new billion-barrel play is about 3%.
“That’s giving us an overall probability of about 3% for a frontier well opening a new billion-barrel play,” Collard said.
