ADX Energy Ltd (ASX:ADX), an Australian energy company focused on oil and gas exploration and production, has announced the resumption of testing at the Welchau-1 well in Upper Austria. The company holds a 75% economic interest in the Welchau-1 discovery, located within the ADX-AT-II permit. Testing had been interrupted in January 2025 due to objections from environmental non-governmental organisations, but the Upper Austrian State Administrative Court ruled in September 2025 that ADX could resume activities.
The focus of the current program is the Reifling Formation, the shallowest of four fractured carbonate reservoirs intersected by the Welchau-1 well. Preparations for flow testing are complete, and the well is now ready for acid stimulation. This process, commonly used in carbonate reservoirs, aims to overcome formation damage that occurred during drilling and enhance productivity. The objective of the flow testing is to determine the hydrocarbon content and flow characteristics of the Reifling Formation.
According to ADX, the Reifling Formation is believed to be near the oil-water contact of a light oil accumulation within the Welchau anticline. This anticline is mapped approximately 500 metres updip from the Welchau-1 well. The company reported that the Welchau-1 well encountered hydrocarbon shows over a 450-metre interval, intersecting three primary carbonate reservoirs considered promising for further appraisal. Recovered light oil confirmed the presence of a light oil system.
ADX considers Welchau a strategically significant gas condensate and potential light oil discovery. The company notes that pressure and structural data indicate an interconnected petroleum system with substantial gas condensate resources. Further updates will be provided following the results of the testing program and ongoing geological studies.
