Key points:

• The Welchau-1 gas exploration well was spudded on the 24th of February using the RED Drilling & Services GmbH (RED) E200 drill rig in the ADX-AT-II exploration licence in Upper Austria.
• Operations at 6.00 pm Central European Time (CET) on the 17th of March - the well had reached total depth (TD) of 1733 metres measured depth (MD) in the 8 ½ inch hole.
• Progress since the last report on the 10th of March has been the drilling of 8 ½ inch hole from 930 metres MD to a depth of 1733 metres MD and the retrieval of 7 metres of core from the primary target formation.
• The success case forward program is to run wireline logs then undertake down hole pressure measurement, inflow testing and formation fluid sampling across the zones of interest prior to running 7 inch casing and suspending the well.

Well results from drilling and logging to date are as follows;

• 115 metres of liquids rich gas shows intersected in the primary target formation “Steinalm Formation” at depth between 1452 metres and 1567 metres. The deepest gas shows were encountered in the well at a depth of 1645 metres MD.
• The Steinalm Formation intersection in the well is in line with the pre-drill prognosis providing confidence in the structural model for Welchau.
• The Steinalm Formation intersected in Welchau is the same zone that flowed condensate rich gas in the nearby Molln-1 well at a rate of 4 MMSCFPD in 1989.
• Compositional analysis from gas shows at Welchau indicates very similar condensate rich gas to the gas tested at the Molln-1 well.
• The well has encountered 380 metres of effective seal “The Lunz Formation” above the main target. Seal quality and thickness was a key risk that has been mitigated based on the results of Welchau-1.

ADX Executive Chairman, Mr Ian Tchacos, said, 
“The Welchau gas discovery has the potential to yield an exceptional gas resource for ADX, its partner MCF and the Republic of Austria. The results to date are in line with pre-drill expectations confirming the exceptional geological and technical work by our Vienna team supported by local and international experts. Over the coming week ADX plans to execute its success case evaluation program for the well which will include electric line logging, down hole sampling, inflow testing and pressure measurement required to confirm the reservoir characteristics and the hydrocarbon composition. We look forward to providing further results on this potential play-opening discovery as they become available.”

ADX Energy advises that the Welchau-1 well has encountered 115 metres liquids rich gas column within the primary target “Steinalm Formation” at depth between 1452 metres and 1567 metres measured depth (MD). At 6.00 pm CET on the 17th of March 2024 the well had reached a total depth (TD) of 1733 metres. The well is being drilled using the RED E200 drill rig in the ADX-AT-II exploration licence in Upper Austria.

Since the last report on the 10th of March 2024, the well was drilled from 930 metres MD to a depth of 1733 metres MD in 8 ½ inch hole. A 7metre core section has been cut and retrieved from the primary target formation (Steinalm Formation).

The success case evaluation program is to run wireline logs then undertake down hole pressure measurement, inflow testing and formation fluid sampling across the zones of interest. The well will then be cased and suspended.

Well results to date 

The well has encountered 380 metres of seal the “Lunz Formation” above the “Steinalm Formation” which is the primary target for the Welchau-1 well. The thick intersection of Lunz Formation is expected to provide an effective seal for the potential hydrocarbon accumulation at Welchau. Seal quality and thickness was a key risk which appears to have been mitigated.

Electric line logs and dipmeter data from the well has confirmed that the Welchau structure is an east-west trending, asymmetric anticline as predicted by ADX in the pre-drill structural model.

The Steinalm Formation was intersected at approximately 1452 metres MD which is line with pre-drill prognosis providing further confidence in the structural model for Welchau. The Steinalm Formation is the same zone that was tested in the down dip Molln-1 gas discovery well which flowed condensate rich gas at a rate of 4 MMSCFPD in 1989. Compositional analysis of gas shows encountered at Welchau indicates a very similar condensate rich gas to that tested at the Molln-1 well.

Liquid rich gas shows were encountered over an interval of 115 metres in the Steinalm Formation between 1452 metres and 1567 metres. The deepest gas shows were encountered in the well at a depth of 1645 metres MD. Drilling data suggests that the Steinalm Formation is an extensively fractured carbonate. Gas shows composed of Methane (C1) to Iso Pentane (C5) have been encountered throughout the section. The C1 to C5 ratio plots indicate the presence of permeable reservoir.

A 7 metre core was recovered from 1511 metres to 1519 metres MD in the Steinalm Formation to gather information on the rock properties (lithology and mineralogy, stratigraphy, petrophysical properties) and to have a calibration section for log interpretation. The cut surfaces of the core confirmed the presence of a natural fracture system which is essential for gas production performance.

The well continues to be drilled efficiently and safely with minor drilling mud fluid losses. Well penetration rates returned to a level which was anticipated in the original well plan. Gained savings in drilling the 12 ¼ inch section will likely result in a success case well program in line with the predicted dry hole cost.

KeyFacts Energy: ADX Energy Austria country profile