The assets, to be purchased from US-based Stanley Energy, comprise a 21% equity in the 240-acre crestal portion of the Jonah Field and 16.6 % of a gross acreage of 12,500 acres in the Lookout Wash Field.

Both of these fields are currently producing net gas of 3.2 million cubic feet, which is expected to increase to 4.2 million cubic feet for this year.

Samson already has a focus in the Green River Basin, since it acquired Kestrel Energy, which has an extensive acreage holding in the region.

Dependent on financing, the transaction is retrospective to November 1, 2005, taking advantage of strong gas prices towards the end of last year, according to the company.

Oil and gas advisory consultants Sproule Associates Inc, estimate the fields contain significant reserves. The total proved reserve has been estimated at 26 billion cubic feet of gas, with total proved, probable and possible reserve at 42 billion cubic feet.

"It is expected that subsequent to the effective date of the transaction, at least three wells will have been completed,” Samson managing director Terry Barr said.

"The first of these has been completed and the rig is currently drilling the second of three wells.”

Barr said the proved undeveloped reserve was largely located in the Look Out Wash Field, in which the field operator has two drilling rigs on long-term contract, currently active in the field.

“Thus whilst the drilling rig market remains tight, because of the substantial gas prices, these un-developed reserves are being brought into the market,” he said.

Samson has a unilateral right to extend the closing date, first scheduled to occur 30 days after execution of the purchase and sale agreement, for up to an additional 90 days by payment of an amount of up to US$2.25 million. This would credit to the purchase price at closing but which would be non-refundable in the event of non-performance, the company said.