A forecast 22 per cent jump in spending to hunt for new oil and gas discoveries has provided fresh evidence that exploration is emerging from the doldrums, despite the escalation in campaigns by environmental and some investor activist groups arguing that new fossil fuel fields need to stay in the ground.

The estimate from consultancy Rystad Energy would see capital expenditure on exploration in the region surge to $US2.2 billion ($3.3 billion) in 2020, with wildcat wells - pioneering wells in unexplored areas - the biggest contributor.