Finder business development manager Craig Gumley told Energy News that the well, the first onshore well for Finder and the first operated under its own name, has spudded using the DDH Drilling Rig-31 which was recently released by Buru Energy.

"We are just running our casing before embarking on our 750m continuous coring program on the way down," Gumley said.

Theia-1, in EP 493, is testing the Middle Ordovician Goldwyer III liquids-rich resource play in a location that the junior explorer believes in the best in the basin.

ConocoPhillips, New Standard Energy and Buru Energy have all tested a number of Goldwyer Shale locations in recent years, but the results of the modern wells did not excite anyone, with Buru electing to focus on the Laurel Formation and ConocoPhillips pulling out.

That's despite all the data from wells going back decades showing the shale formation has significant promise, with the US Energy Information Administration identifying the basin as having in excess of 225 trillion cubic feet of recoverable shale gas, based on the Goldwyer alone, which dwarfs the 38Tcf of recoverable shale gas in the liquids-rich Laurel Formation estimated by The Australian Council of Learned Academies.

The Goldwyer sits at depths between 1000-2500m on the Broome Platform where Finder is drilling, and is expected to be oil prone, and up to 140m thick with good total organic contents of TOCs of 3-7% and porosities in excess of 8%.

The Goldwyer Shale resembles the Bakken Shale in the US, with a middle limestone-rich member that may be oil productive, in addition to the organic-rich black shale at the base of the formation that is the primary exploration target, and there are strong similarities between the Utica Shale in Ohio and the Marcellus Shale in Pennsylvania.

Finder believes everyone else has been looking in the wrong spot, and it is so-convinced with its pre-drilling work that the company is putting up its own limited cash into the drilling of the 1800m well.

The well will be drilled slim-hole to reduce costs, maximise data capture and reduce its environmental footprint.

At Theia-1 Finder believes the shale will be above 2000m and isolated from the overlying Grant Formation, so any hydrocarbons generated in the thick shale will not have migrated away.

The Bongabinni Shale and Nita Formation, secondary targets, will also be drilled through.

The main focus of the well is the data capture aspect, "because you can't beat real rocks", Gumley said.

Finder has looked at the McLarty-1 and Edgar Range-1 cores, earlier wells drilled near to its 4610sq.km permit, says it has defined a sweet spot with predicted overpressure on the Broome Platform.

Finder says the Goldwyer III sweet spot is about half the size of the productive Eagle Ford Shale in the USA.

There are shows all around the block, notably the Pictor field where the Goldwyer was 400m thick, and the promising Looma-1 well.

The aim is to complete specialised geotechnical analysis to evaluate shale porosity, permeability, rock strength and stress regimes, and conduct a wireline logging program to calibrate the Theia-1 core to wireline logs and extrapolate these learnings to un-cored sections of existing and future wells within the Canning Basin.

As a source rock, Finder says the Ordovician marine claystone should be as good as or better for liquids generation than those seen in China's tectonically related Tarim Basin, which is responsible for China's largest liquids discoveries.

The company is now banking on an outstanding result from the well, which could shed light on the potential of the Goldwyer Shale, which past focused exploration - what little there was of it - has proven difficult to predict.

With good numbers, or even oil in the core, Finder's next call for a farm-in partner could be very different.

Finder was unsuccessful at finding a partner to come in at the groundfloor, despite offing a bottom-hole contribution with an attaching exclusive no-obligation option to participate in the year two work program, which requires 220km of new 2D seismic and a further two exploration wells over the next two years.