The NT Survey’s Greg Ambrose said much had changed in the few years since two technical symposiums were held to promote new oil and gas plays in the Territory.
In the Timor Sea, the technical discovery rate has rocketed from 25% to 80% over the past three years, while back on dry land the Government is currently sifting through 22 licence applications, 10 of which have already been granted.
And even though large portions of acreage have already been snapped up on the back of this work, there are still many areas with vast untapped potential, according to Ambrose.
Red centre, black gold
Ambrose enthused about the onshore NT, which he said was “steaming ahead very nicely” and was due to receive about $55 million of exploration funding over the next five years.
“The geology out there is absolutely enthralling,” he said.
“We’ve got proven oil systems in the Amadeus [Basin], the Pedirka Basin with a lot of similarities to the Cooper and new seismic and drilling to begin in the Beetaloo this year.”
So what can explorers expect – or at least hope – to find in the outback? Ambrose says there is huge potential for both crude and natural gas but the economics are most favourable for oil.
“A good road network means the trucking option is a favourable and low-cap one for oil discoveries,” he said.
“Local markets are going to be the key driver for onshore gas discoveries. But there are possible openings, such as at Alcan’s refinery in Nhulunbuy and at MacArthur River, and then there’s Central Petroleum’s gas-to-liquids plant.”
Comprising 30 technical papers, the Central Australian Basins Symposium (CABS), is expected to be fully published and completed in the next few months, according to Ambrose.
Offshore frontiers
Ambrose described the 2003 Timor Sea Symposium as a “turning point” for the offshore region, followed by numerous successes such as AED Oil’s Puffin oil field and several other smaller oil discoveries by Coogee Resources.
“Excellent potential exists for small-to-moderate sized oil pools and we’ve got excellent potential for large gas fields, which will eventually lead to the second LNG train for Darwin,” he said.
A new offshore oil play – dubbed Plover Deep – has received much attention and is being pursued by “a number of exploration companies” since the idea was floated at the symposium, according to Ambrose.
So what’s pushing explorers into frontier regions such as the Timor Sea? While higher oil prices are one reason, the Australian Government can take the credit for another big motivator.
Recognising that Australia’s liquid petroleum trade deficit is costing the country billions of dollars each year, Resources Minister Ian Macfarlane in 2004 launched the Government’s Big New Oil campaign. Then in mid-2006, the Government injected a further $135 million into the program.
The first part of the scheme involves offering explorers a 150% tax concession for venturing into these offshore frontier basins.
The second part places new focus on Geoscience Australia’s role in providing pre-competitive geological groundwork in these regions.
Over the next five years, the agency will acquire information across 2 million square kilometres of ocean – more than three times the area covered in the earlier program.
There are many basins of interest.
Those in the north include the offshore Canning Basin near Broome WA; the outer Exmouth Plateau moving into ultra-deep water off the northwest coast; the Arafura and Money Shoals Basins north of Arnhem Land in the Northern Territory; and the Bamaga Basin in the Gulf of Carpentaria.
To the east lies the Sydney Basin off the coast of Newcastle and Sydney.
In southeast there are the Durroon Sub-basin in the eastern sector of the Bass Basin near Flinders Island, Tasmania; the Sorrell Basin west and northwest of Tasmania; and the outer Otway Basin in Tasmanian and South Australian waters.
The Bight Basin off South Australia and Western Australia is considered to be one of the world’s largest frontier basins and has four depocentres.
To the southwest, there are the Bremer Sub-basin off the south coast of WA; the Mentelle Basin off the southwest tip of WA; and the Vlaming Sub-basin in the southern offshore Perth Basin, stretching south from Fremantle to Margaret River.
Geoscience Australia maintains that Australia probably has the largest spread and variety of offshore frontier basins of any country in the world.
And with industry having barely scratched the surface, there is every reason to believe a major new oil province could be waiting to be discovered.
APPEA 2007’s Frontier Potential session on Tuesday afternoon will include three presentations.
Geological Survey of Queensland’s John Draper will speak on the Georgina Basin – an early Palaeozoic carbonate petroleum system; Greg Ambrose from the Northern Territory Geological Survey will outline the petroleum geology of the Middle-Late Triassic and Early Jurassic sequences in the Simpson Basin and northern Eromanga Basin; and Frogtech’s Lynn Pryor and Jane Blevin will provide a terrane analysis of the Lord Howe Rise Region and what implications petroleum prospectivity could have in that remote frontier region.
