Gas shows were recorded with two peaks of 500 and 600 units over an 80-unit background, the company said.

The sidetrack drilling was designed to bypass a mechanical restriction in the casing, which occurred five years ago during fracture stimulation and stopped the sandstone from flowing gas.

Greens Canyon-2 will be drilled to 4687 metres to set a 3.5-inch casing. The Muddy Sandstone expected to be fracture stimulated next month, subject to availability of frac equipment.

Samson has described Greens Canyon as a low-risk development that benefited from the presence on-site of a pipeline.

"At Greens Canyon, we've got the ability for any discoveries to go straight into the bottom line, so that's why it's a priority target for us," managind director Terry Barr said.

Samson's 100%-owned Greens Canyon Gas Field is in the Green River Basin, Wyoming, west of Rock Springs township.