ADX Energy Ltd (ASX: ADX) has recovered hydrocarbon gas and light oil at its Welchau-1 well in the ADX-AT-II licence in Upper Austria. The recovery occurred during well unloading operations as part of ADX Energy flow testing of the 128-metre thick Reifling Formation. The Reifling is the shallowest of four fractured carbonate reservoirs intersected at the Welchau-1 well.
Figure 1: Light oil sample recovered from the Reifling Formation at the Welchau-1 well during flow testing on 16 February 2026 [ADX Energy]
The ADX Energy light oil recovery is consistent with the Company’s structural interpretation of a large light oil accumulation updip from the Welchau-1 well location. Compositional analysis of oil and gas samples is currently underway. The well has been suspended to record pressure build-up and fluid inflow while results are assessed.
ADX Oil Discovery Austria: What the Reifling Formation Testing Revealed
The ADX Energy flow testing program at the Reifling Formation produced a series of technically meaningful results:
- Light oil recovered from the Reifling Formation matched the same density as oil recovered from the deeper Steinalm Formation during the original drilling of Welchau-1
- The absence of biodegradation in oil sampled within both the Reifling and Steinalm Formations, combined with an observed overpressured system, is indicative of an updip live oil accumulation
- A small acidisation treatment of 6 cubic metres across 45 metres of perforations successfully induced inflow from a previously unresponsive reservoir
- Hydrocarbon gas and light oil were recovered and sampled at the surface during swabbing operations
- Insufficient inflow was achieved from stable flow, indicating the small volume acid treatment did not access the open fracture network
- A Reifling Formation reservoir pressure has not been recorded to date, with the well suspended to monitor pressure buildup
Figure 2: Regional map highlighting the Molln Gas Fairway and the interpreted updip light oil potential at Welchau [ADX Energy]
ADX Energy Light Oil Recovery Supported by Updip Structural Interpretation
The ADX oil discovery in Austria is underpinned by a specific geological interpretation. The crest of the shallow Welchau anticline is mapped approximately 500 metres updip and to the west of the Welchau-1 well. This crest is interpreted as the location of a light oil accumulation in the Reifling Formation.
Figure 3: Interpreted oil-water contact for the updip light oil accumulation within the Reifling Formation at WEL-001 [ADX Energy]
ADX holds a 75% economic interest in the Welchau-1 discovery. The Welchau-1 well encountered hydrocarbon shows over a 450-metre interval intersecting three primary carbonate reservoirs.Â
Pressure and structural data demonstrate pressure continuity and aquifer communication between Welchau-1 and the downdip Molln-1 discovery, which is a historic gas discovery that tested gas condensate within what is interpreted to be the greater Welchau anticlinal structure.
ADX Energy Flow Testing: What Comes Next at Welchau-1
ADX Energy flow testing will continue with further evaluation underway. The Company is assessing a larger acid stimulation of the Reifling Formation using a coiled tubing unit. This approach aims to access the open fracture network within the formation, which the initial small-volume treatment did not reach.
Figure 4: Surface outcrops of the marly and fractured Reifling Formation illustrating reservoir characteristics [ADX Energy]
Beyond the Reifling Formation, the Welchau play holds a broader set of appraisal options. Further work can be undertaken via a side track of the Welchau-1 well to target updip light oil, or by deepening the well to target the gas condensate potential at depth.Â
Welchau is characterised by overpressured reservoir conditions with multiple petroleum sources across several formations, making it a strategically significant position within the ADX-AT-II licence in Upper Austria.
ADX Oil Discovery Austria: Background on the Legal Delay and Court Ruling
The ADX Energy flow testing program at the Reifling Formation was interrupted in January 2025. Environmental non-governmental organisations lodged objections related to the environmental clearances provided to ADX for the drilling and testing of Welchau-1.Â
The matter proceeded to the Upper Austrian State Administrative Court, which ruled in September 2025 that ADX may resume testing activities at the Welchau-1 well.
Testing subsequently resumed with the acid treatment designed to initiate flow. The legal interruption delayed the ADX Energy flow testing program by several months but did not affect the physical integrity of the well or the underlying reservoir interpretation.Â
The Company has maintained its structural interpretation throughout and says the current results are consistent with that view.
Share Price Performance
ADX Energy Ltd (ASX: ADX) last traded at $0.030 per share. The 52-week range is $0.022 to $0.045 per share. Market capitalisation is approximately $22.67 million.
Figure 5: ADX Energy Ltd share price performance over the past year, showing recent stabilisation following volatility through 2025 and early 2026 [ASX]
Investor Outlook
The ADX Energy light oil recovery at Welchau-1 is an encouraging development for a Company with a market capitalisation of $22.67 million. The result confirms the presence of live hydrocarbons in the Reifling Formation and supports the updip accumulation interpretation. Key watchpoints for investors include:
- Results of compositional analysis of oil and gas samples are currently being undertaken
- Pressure build up data from the suspended well
- Decision on larger acid stimulation using a coiled tubing unit
- Potential side track or deepening of Welchau-1 for further appraisal
- Ongoing geological studies and updated structural mapping
Frequently Asked Questions
Q1. What is the ADX Energy light oil recovery at Welchau-1?Â
Ans. ADX Energy recovered hydrocarbon gas and light oil from the Reifling Formation at the Welchau-1 well in Upper Austria during well unloading operations as part of flow testing at the ADX-AT-II licence.
Q2. What makes the ADX oil discovery in Austria significant?Â
Ans. The ADX oil discovery in Austria is significant because the light oil recovered matches the density of oil from deeper formations, lacks biodegradation and is consistent with the Company’s interpretation of a large updip light oil accumulation approximately 500 metres from the well location.
Q3. What is ADX Energy flow testing targeting next?Â
Ans. ADX Energy flow testing is evaluating a larger acid stimulation of the Reifling Formation using a coiled tubing unit to access the open fracture network that the initial treatment did not reach.
Q4. What is ADX Energy’s ownership interest in Welchau-1?Â
Ans. ADX Energy holds a 75% economic interest in the Welchau-1 discovery within the ADX-AT-II licence in Upper Austria.
