Westwood found global drilling levels were maintained over the past year with 79 high impact wells completed in 2021 compared to 78 in 2020.

However, discovered resources dropped 65% year-on-year to 6.7 billion barrels oil equivalent.

Australia suffered from significantly reduced exploration drilling over 2021 with just 29 wells completed over the year.

Notably, only 10 nominations have been received for the latest Australian offshore acreage round this year, just under half what was bid for in 2021 and less than a quarter of the interest in 2020.

In stark contrast, global oil and gas exploration activity is at its highest levels since 2016 - with the exception of 2019 when 98 high impact wells were drilled.

Westwood found that exploration was increasingly dominated by Supermajors and National Oil Companies.

Together, the account of around 70% of high impact well spending. This is about 20% higher than 2018.

"There is an opportunity for smaller companies to participate in high impact exploration activities, but funding for developments in the success case may be a challenge," Westwood said.

The latest high impact well in Australia is the Sasanof-1 wildcat offshore Western Australia which was spud this week.

It will target a 2U prospective resource of 7.2 trillion cubic feet gas and 176 million barrels of condensate. On a high case 3U basis, the resource estimate is 17.8 Tcf gas and 450MMbbls.

Westwood found that frontier drilling was likely to see a "short-lived bounce back" from a 14-year low in 2021.

Just 16 frontier wildcats were drilled in 2021 with just one minor success. This year there have been three frontier successes so far.

Frontier drilling success rates have been less than 10% for the better part of a decade.

"There is still an appetite for exploration for new plays, particularly those that can be commercialised quickly, but the pool of active frontier drillers has shrunk," Westwood said.

In 2019 there were 52 active frontier explorers. Last year there was just 24.

Westwood said companies were now taking a more purposeful approach in their exploration campaigns, with an emphasis on infrastructure development rather than scouting new regions.

Exploration with purpose has resulted in higher commercial success rates, averaging 47%, but smaller discoveries.

Exploration successes that can be brought on stream quickly remain attractive as companies seek payback before demand for hydrocarbons declines.

"Underpinning all future exploration activity is a requirement for low emissions intensity developments. Prospects will be chosen for drilling based not just on volumes and chance of success but increasingly on time to break even and the success case impact on company net zero targets," Westwood said.