The Otway Basin has been identified as one of the two most promising onshore basins in SA, and one of two with gas production, but Rawson - which tried to spin the blocks off unsuccessfully as Otway Energy several years ago - has been unable to fund drilling of a number of gas prospects.
The Otway Basin is one of the more actively explored basins along the southern margin of mainland Australia, yet the onshore western portion of the basin remains relatively underexplored despite the presence of a number of modest gas discoveries around the Katnook area between 1991 and 2011 and small oil pools such as Killanoola-1 and Jacaranda Ridge-1 in the 1990s.
While the company has been interested in drilling targets in the Pretty Hill Formation, Windmere Sandstone and the Waarre Sandstones, and the longer-term potential of the Sawpit and Casterton shales, the company says it no longer has the fire to explore within PEL 154 and PEL 155, which are close to the South Australian/Victorian border.
There are two prospects mapped on 3D in the blocks - Benara and Nangwarry, and the Benara East lead - and despite a number of reviews and extensions, it seems likely Rawson will not be in a position to drill the prospects in 2018 and 2019 as expected.
The company's directors have changed since it spent $2 million on Hardie Energy's 62.5% stake in 2014, and they are now focused on wildcat exploration in Papua New Guinea's northern coast.
Rawson told the ASX yesterday it viewed recent work over its frontier PNG licences as encouraging enough to consider shedding the Otway assets and well its 10% interest in the Udacha gas-condensate field in the Cooper Basin, and become a PNG-focussed company only.
Rawson has three licences and two applications in PNG.
In PPL 391 it said early promise from the testing of wells in the 1930s had led it to conduct a more extensive sampling campaign to better understanding the flow potential of the reservoir.
It said an independent analysis by Petrolab and show the Matapau oil to be a light crude with an API of 28.8, which sits at a shallow depth, right on the coast.
In PPL 560 the company is reviewing existing seismic interpretation techniques, and it says there is strong support for the presence of a flat spot on the seismic co-incident with the Buna prospect, which further supports a potential well.
In 2010 the PPL 560 prospects were estimated to hold a potential 6.5 trillion cubic feet (mean) by Fekete Associates for a former permit owner.
Rawson has commissioned a regional geological expert who is reviewing and derisking the Buna prospects.
Rawson shares were 3.2 cents this morning.
