ADX Energy points to mammoth Austrian gas upside

After exhaustive mapping and technical work, ADX Energy has thrown down the gauntlet in Austria, upgrading its Welchau-1 gas discovery to a chunky mean prospective resource of 387 billion cubic feet (Bcf) of gas and 31 million barrels (MMbbl) of light oil and condensate.

On the high side, the potential prize nudged almost one trillion cubic feet of gas and 76.9 million barrels of liquids.

Welchau-1 was originally drilled in early 2024 to target gas-condensate up-dip of the historic Molln-1 well, which was drilled by Austria’s largest oil and gas company, OMV, and flowed at 3.5 million cubic feet per day when tested in 1989.

Instead of just gas, ADX struck something else along the way – light oil. The well cut 450 metres of hydrocarbon shows across four fractured carbonate reservoirs between 1281m and 1731m. A 43.6 degree API light oil was confirmed from downhole samples, with oil recovered from two shallow horizons called the Steinalm and Reifling formations.

Mapping suggests the crest of the oil structure sits about 500 metres up-dip from the current well position, indicating the well appears to have intersected the lower part of a potentially larger oil accumulation.

Adding to the excitement, ADX says the well has still not reached its main gas-condensate target. The pressure readings and geological data suggest continuity between Welchau-1 and the deeper Molln-1 discovery further down the structure, pointing to an extensive, interconnected petroleum system.

Two deeper gas targets sit below the current casing, and the closer one could be tested simply by drilling the existing well another 600 to 700 metres deeper. That relatively modest extension could open the door to the bulk of the 387Bcf mean gas resource the company is now flagging.

The results of Welchau-1 to date confirm that a potentially substantial light oil accumulation has been encountered in the well. The well has not yet intersected the primary gas condensate objective we set out to drill and test in February 2024.

Although Welchau-1 was first drilled almost two years ago, a regulatory subplot delayed the flow tests in January 2025 after objections from environmental groups. Austria’s State Administrative Court subsequently dumped the objections in September last year, allowing ADX to resume operations.

With testing back on track and compositional analysis underway, the company has suspended the well to monitor pressure build-up and fluid inflow while it sharpens plans for the next move.

From here, ADX has two obvious pathways. It can sidetrack up-dip to chase the interpreted light-oil crest, or deepen the existing hole to drill into the mapped gas-condensate duplexes below. Either way, Welchau is shaping up as more than a single-zone punt.

For a junior with exposure to European gas markets, 387Bcf of prospective gas and 31MMbbl of liquids is not small change. The big question now is whether a 600-metre deepening can convert that prospective resource into something far more tangible.

If it does, Welchau could move from an intriguing Alpine structure to a strategically important domestic energy play at a time when Europe is hungry for secure supply.

Is your ASX-listed company doing something interesting? Contact: matt.birney@wanews.com.au