Until Apache and Carnarvon Petroleum announced their highly encouraging Phoenix South discovery in the previously barren offshore Canning Basin the outlook across the oil and gas sector was rather gloomy.

Construction cost blow-outs, completion delays and industrial disputes have been dogging Queensland’s emerging coal-seam based LNG projects, while on the western side of the country the preference has been to delay rather than proceed with developments.

A lack of exploration success added to the sense of despondency that came to a head when institutional shareholders rolled the board of Woodside Petroleum, which had proposed an unequal share buyback to largely complete the removal of Royal Dutch Shell from the Woodside share register.

It was with this background, plus a relatively low oil price and concern about US gas exports flooding Australia’s backyard market of Japan and China that the Apache and Carnarvon-led consortium announced their offshore Canning Basin discovery.

In terms of geological importance the Phoenix South well is among the most significant made in Australia in the past 50 years.

Not only does it potentially open up a suite of exploration targets, it can also be seen as the missing link between the prolific offshore Carnarvon Basin to the south and the Browse Basin to the north.

Previous attempts to close the gap failed for a variety of reasons despite one of the oil industry’s giants, Armand Hammer, boldly predicting a few decades ago that the Canning Basin would one day be a prolific as the oilfields of Libya.

Much more drilling is required to prove that Phoenix South is the missing link but investor enthusiasm for what has happened so far can be seen in the Carnarvon Petroleum share price. It effectively tripled in the days after last Monday’s discovery announcement with the stock rushing up from 8.1c to a 12-month high of A28.5c on Tuesday.

Carnarvon’s share price has since settled back to around 21.5c but that is still 165% higher than a week ago.

Phoenix South, significant as it could turn out to be was just the start of a remarkable good-news weeks for Australian oil and gas.

On Friday Santos chimed in with what could be an equally important discovery, this time in the Browse.

The Lasseter well, located close to the Ichthys project, could be big enough to justify the development of additional trains at the Darwin LNG project.

Located 35km southeast of another Santos discovery, Crown, the Lasseter well encountered a gross condensate bearing interval of 405m. Logs have so far revealed 78m of net pay with the potential of more to come.

Like Phoenix South the latest Santos discovery needs more work though to have two significant finds reported in the same week is big fillip for the local industry.

The week finished with encouraging news, a claim from head of BP in Australia that its planned exploration in the Southern Ocean off the Great Australian Bight could produce a discovery to rival the oilfields of Nigeria or the Gulf of Mexico.

It is highly unlikely that the company’s local head, Andy Holmes, gave anything other than a broad-brush estimate about the potential of the Southern Ocean and was probably surprised to read that his best guess had become a headline proclaiming hope of “tapping a new world-class oilfield”

As everyone in the oil game knows there is a long way between planning a drilling campaign and making a big discovery.

What Holmes was probably trying to say is that BP will give the Southern Ocean its best shot and is prepared to toss a few billion dollars at the wildcat potential of a new frontier in offshore conditions to rival anything encountered by drilling crews in the North Sea.

But to go the next step and compare the region off southern Australia with Nigeria or the Gulf is stretching credibility a long way given the past lack of success and the present problem of a sluggish oil price caused by a worldwide oversupply of oil and gas.

Perhaps Holmes was getting caught up in the buoyant mood that developed last week thanks to the potential game-changing nature of the Phoenix South and Lasseter discoveries.

Whatever the explanation, and however excessively optimistic his comments were about the Southern Ocean, last week could have been the turning point for Australian oil and gas, which has been in need of discovery news to stimulate interest and boost exploration activity.