The company has also been advised that rig operations have been suspended due to an investigation by Santos after an incident occurred on Sunday evening.

No one was injured and there has been no environmental impact.

The well reached its programmed total depth of 2295m after drilling into the target Heavitree formation at 2140m, intersecting a formation thickness of 109m.

Elevated gas readings were recorded upon penetration of the formation, with a flow test at 2144m initially producing 500,000 cubic feet per day, before declining to 70,000cfd after 10 minutes.

A test at 2156m produced 530,000cfd, decreasing to 420,000cfd after 18 minutes accompanied by a gas flare and no water.

Other comparable flow rates were recorded at 2185m and 2252m.

Preliminary analysis at the well indicates a high helium content to the gas, making up about 5.8%

Helium is around 30 times more valuable to the joint venture than methane.

"Whilst it is too early to speculate on the commercial significance of the gas discovered in the Mt Kitty 1 well until logging operations are completed and gas samples are analysed, it should be noted that the geological parameters known to date are aligned with, if not better than, those expected prior to drilling for example, the gross Heavitree thickness is better than expected prior to drilling," Central Petroleum managing director Richard Cottee said.

Wireline logging operations had begun just prior to the rig being shut down for investigation into Sunday's incident.