Tamboran, which revealed the existence of the dispute last year during a failed funding arrangement with Houston American Energy, which was planning to take a 12.5% interest in the junior, has previously refused to provide any specific details about its claim that Santos has breached the terms of a 2012 farm-in agreement and had forfeited its rights to three promising leases.
The Australian Financial Review this morning quoted documents lodged by Tamboran with the Australian Securities and Investments Commission in support of a placement to the Paul Fudge-backed Geotech Investments, which said Tamboran was confident of securing 100% of its permits in a successful claim against Santos.
"Management believe that a high case scenario would result in Tamboran controlling 100% of the licence, with the low case being a 25% interest," the paper quoted a BDO document.
Santos was earning 75% by spending $71 million over two phases.
In the first phase it would earn an initial 50% stake by funding $41 million of work over three years, including the drilling of Tanumbirini-1.
The well, drilled in 2014, was one of the deepest onshore wells to have been drilled in Australia at a total depth of 3945m.
Multiple thick intervals of organic-rich rock were intersected at the primary objective Mid-Velkerrie level, accompanied by significant mud gas shows.
Elevated gas readings were encountered over a total gross interval in excess of 500m.
A 90m core was taken and extensive wireline evaluation conducted. The well has been cased and suspended, and since that time Origin Energy has fracced the nearby Amungee-1 NW well and flowed gas at more than one million cubic feet per day.
The results have helped support predictions that the Beetaloo Basin area of the Greater McArthur Basin could hold trillions of cubic feet of gas.
Tamboran's leases also contain the Urapunga-4 oil shows.
Last year Santos, which described the McArthur Basin leases as a core area in its reorganisation, said the Beetaloo leases are akin to some of the best-performing shale zones in the US.
However the dispute with Tamboran meant a planned three corehole program to earn its 75% interest bid not proceed last year.
The AFR said that Santos had not met the time window to commit to the second phase, although preliminary findings from the arbitrator are understood to have deemed that argument invalid.
A decision in the ongoing arbitration is expected in June.
Last year Tamboran struggled to raise $710,000 required as a condition of its deal with Houston American Energy.
The arrival of Geotech, which is linked with Fudge, who has leases of his own in the Beetaloo via Pangaea Resources, suggests its funding issues may have eased despite the NT's moratorium on fraccing.
Tamboran has also a long-held desire to redrill the Davis-1 well in the frontier Ngalia Basin, to assess the unconventional potential. That well was drilled by Moonie Oil in 1981 to almost 2000m and encountered minor gas shows in the Mt Eclipse Sandstone.
Tamboran, which claims the whole of the Ngalia Basin, believes the Rinkabeena Shale could contain up to 100Tcf of gas in place, just off the Darwin pipeline.
To date Davis-2 has not spudded.
Tamboran was founded by Eastern Star Gas co-founders Patrick Elliot and Dr David King and counts on its board Petrohawk Energy co-founder Dick Stoneburner.
