Cougar lifted the JORC-compliant resource from a 73Mt base to 307Mt inferred and 34Mt indicated resource.

The upgrade exceeded expectations of 200-300Mt.

“This is a high-quality coal resource upon which to develop a second UCG project with our UCG technology partner, Ergo Exergy Technologies Inc,” Cougar managing director Len Walker said.

“The coal deposit is in the same coal seam as the nearby Chinchilla deposit, where previous underground gasification tests were successfully conducted by Dr Michael Blinderman [Ergo Exergy CEO] and myself some 10 years ago. This gives us great confidence in the product gas we can produce from the site.”

Cougar closed up 5% to 10.5c yesterday.