The Adelaide-based oil and gas producer said the Thomas Bright-1 exploration well had upgraded the gross resource potential of the John Brookes field to up to 1000 petajoules (PJ) of gas.

Santos managing director John Ellice-Flint said the John Brookes field is close to existing infrastructure and that Santos is actively engaged in negotiations to commercialise the field.

"The Thomas Bright-1 result has exceeded our expectations," Ellice-Flint said. "The result has increased the expected gas volume by 25 per cent on our interpretation prior to drilling."

The John Brookes field was discovered in 1998 with John Brookes-1, which flowed at 37 million cubic feet per day.

Thomas Bright-1 is located 2.3 kms southwest of John Brookes-1, 30 kms north-northeast of East Spar and 56 kms northwest of the gas processing facilities on Varanus Island.

The well intersected approximately 88 metres of net gas within the primary objective Basal Muderong/Upper Barrow target.

The successful result significantly increases the total hydrocarbon resources discovered and appraised by Santos in its Western Australian interests over the last twelve months.

WA 214-P is operated by Apache Northwest while Santos currently has a 28.75 per cent interest in the permit.