IPB unsuccessfully drilled the Pryderi-1 well last year, fully carried by its partner CalEnergy Resources, because it believed success would have unlocked some two dozen immediate follow-up targets.
Sadly, the well was a duster, but it has not shaken the company's faith in its overall geological theory, that the southern margin of the Browse Basin is oil prone.
The channel seismic amplitude anomaly is now understood to be indicative of residual gas in poor quality reservoir rather than the hoped for oil response, but according to Brown the prospect was never the final game, which is the liquids potential highlighted in the heady days of the 1980s in the Gwydion-1 well and, in an adjacent block, the Greater Cornea field.
IPB believes those discoveries confirm that oil has migrated over 100km out of the deep Browse Basin into the area covered by IPB's three large blocks.
Gwydion is an anomaly, with the oil below the spill point, he said.
"Gwydion-1 encountered 14m of gas in a glauconitic reservoir over 11m in very good quality reservoir - 27% porosity, inferred permeability of half a darcy to 3D," Brown said at last week's RIU Good Oil Conference in Fremantle.
Recent work by IPB suggests the well nipped a large stratigraphic oil accumulation, so the company wants a partner to come in and fund a well up-dip of the previously defined Mathonwy gas prospect.
The well would be drilled next year.
The 3D survey data that IPB funded in 2011, and subsequent depth conversion work, has allowed the company to map the Gwydion gas cap to the structural closure, and that means is that the oil leg has to be stratigraphically trapped and far more extensive than previously thought when BHP made the original discovery, Brown said.
"We have a sister gas cap, Mathonwy, and our plan is to drill a well up-dip of that, and that well should establish commerciality of the resources," he explained.
The well can be drilled for about $15 million in just two weeks because it sits in just 80m of water, with the target just 800m sub-surface.
IPB has calculated the prospect could host up to 80-100 million barrels, with its 2C best estimate at 32.8MMbbl.
It could be more laterally extensive than currently capped because IPB has been quite conservative in its assumptions, Brown said.
The commercial threshold for a discovery, even at current prices, is 10MMbbl.
In fact, the company says just proving the oil means there is a 95% chance of commerciality.
Development could be relatively fast.
Just 18 months for further appraisal and front-end engineering and design to a final investment decision, and up to two years of further detailed design, with the field potentially in production by 2020.
Success would open up the potential of IPB's permits, which control the lion's share of the southern margin oil fairway play, and the company is offering optionality over WA-471-P and WA-485-P as part of the WA-424-P farm-out.
Brown said IPB is open to multiple farm-in partners.
