ExxonMobil and Shell were the most active high-impact oil and gas explorers between 2020 and 2024, according to energy intelligence firm Westwood Global Energy Group, even as national oil companies (NOCs) surged ahead in 2024 to dominate both drilling activity and discovered resources.
In its State of Exploration 2025 report, Westwood ranked ExxonMobil as the top driller of high-impact wells over the five-year period, followed closely by Shell, then CNOOC and TotalEnergies. All four companies drilled more than 40 high-impact wells during the period. Other active high impact drillers included Equinor, QatarEnergy, Petronas, Eni, Hess, BP, and Chevron.
Westwood defines high-impact wells as those targeting at least 100 million barrels of oil-equivalent in recoverable resources. Of the 20 most active explorers globally, seven were NOCs.
While the supermajors maintained a strong showing over the broader period, their performance in 2024 was markedly weaker. Westwood analyst Jamie Collard said supermajors accounted for only a small fraction of discovered resources last year and posted a net commercial success rate of just 5%.
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In contrast, NOCs dominated the 2024 exploration landscape, accounting for more than half of all high-impact well equity and around two-thirds of discovered resources. Most of this was driven by domestic NOCs (exploring within their own countries) with a smaller share attributed to their international ventures.
“Domestic NOCs have outperformed the other peer groups most years,” Collard said during a presentation of the findings. He explained that in this segment, these companies are generally operating in geographies that are not open to the rest of the peer groups.
The shift continues a broader trend observed over the past five years. Equity share in high-impact wells has gradually declined for supermajors and large independents, while increasing for state-owned players. Domestic NOCs captured about 50% of high-impact discovered resources over the full period, and another 10% when exploring outside their home countries.
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Despite this shift, Collard noted that several supermajors and large companies remain key players in terms of drilling breadth. Shell, for instance, tested more geological plays (32) than any other company while TotalEnergies drilled across 19 countries, the most geographically widespread footprint in the study.
Among the large independents, Eni and Hess stood out for their continued activity and success rates, contrasting with the declining activity of peers such as BP and Chevron.
QatarEnergy and Türkiye’s TPAO were among the fast-rising NOC participants earlier in the five-year span, though Westwood observed that few new entrants have emerged in recent years.
