Apache is the operator with a 55% working interest and Santos owns the remaining stake. The two companies are partners in several Carnarvon Basin permits.

The Gnu-1 well logged 115.2m of net pay in the Legendre Formation, the main reservoir. This is almost 28m more pay than previously seen in the field, according to Apache.

The Legendre pay zones, located about 1067m uphole from the North Rankin reservoir, will not be tested as an earlier Legendre well tested 35MMcf of gas and 165bpd condensate. When developed for production, the Legendre sands are expected to deliver more than 100MMcf of gas per day.

The North Rankin Formation was tested on a 1.25-inch choke with 954 pounds per square inch of flowing wellhead pressure. Perforations were between 3432m and 3440m measured depth.

The well is about 90km offshore in the northeast section of Apache’s Carnarvon Basin acreage in about 60m of water, according to Apache chief executive G. Steven Farris.

“This well brings our expected gross recoverable reserves at the Reindeer/Caribou field to half a trillion cubic feet of natural gas,” he said.

“We plan to develop this field with an objective of first production in 2008. With five additional seismically defined prospects in the immediate vicinity, the first of which we plan to spud later this year, the growth potential of this area is significant.”

Part of the gas is dedicated to the company’s existing contracts and ample market opportunities exist for the rest, Farris said. Development options, including the possibility of a new pipeline to the mainland, are currently being evaluated.