ADX Energy Ltd.: Welchau-1 Discovery Well to be Cased and Suspended for Future Testing

[ Report ]

Wien (pta017/25.03.2024/11:36) - "Logging results reveal a high correlation between hydrocarbon shows and open fracture networks essential for well productivity over a large gross interval. Down hole sampling tool sticking prevented adequate sampling across zones of interest.

Liquid hydrocarbons and gas inflow was observed at surface following down hole sampling which further confirms existence of mobile hydrocarbons."

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 am Central European Time (CET) on the 24th of March was retrieving Modular Formation Dynamic Tester (MDT) tool which was previously stuck in the well bore and preparing to run 7 inch casing.
* Progress since the last report on the 18th of March has been conditioning the well and running wireline logs, down hole pressure recording and sampling tools.
* The forward program is to condition the well then run and cement 7-inch casing down to the well total depth for well suspension.
* Liquid hydrocarbons and gas inflow to the wellbore were observed at surface following down hole sampling operations further confirming existence of mobile hydrocarbons.
* Preliminary well results from logging, which included image log, sonic log, density log, neutron and resistivity logs and the down hole pressure recording and sampling tool, are summarised as follows;
* A strong correlation between formation open fractures, important for carbonate reservoir productivity, with hydrocarbon shows encountered while drilling the well.
* Strong evidence of vugs in carbonate matrix also coincident with hydrocarbon shows, in drill cutting samples and a 7 metre whole core recovered from the well.
* Fracture networks and vuggy porosity encountered between depths of 1346 metres measured depth (MD) and 1702 metres MD (356 metres gross interval) across three interpreted lithological sequences.
* MDT tested intervals show medium to very high permeability which is in agreement with fracture density and petrophysical log interpretation.
The MDT downhole sampling of the reservoir fluids was unable to sample reservoir fluids from the zones of interest primarily due to the extensive mud losses into the open fractures of the well. Furthermore the sampling procedures were hampered due tool sticking impacting the recoverability of representative samples from the zones of interest.

ADX Executive Chairman, Mr Ian Tchacos, said, "The logging results have confirmed the presence of well-developed open fracture networks and vuggy porosity coincident with hydrocarbon shows. These fracture networks and vugs are key to well productivity in carbonate reservoir systems. Encountering potential productive zones over a gross interval of 356 metres is very compelling. While it is frustrating that the attempted fluid sampling was hampered due to operational difficulties which are relatively common in fractured carbonate reservoirs, the well inflow of hydrocarbons further confirms the existence of mobile gaseous and liquid hydrocarbons that can only be properly evaluated with a cased hole testing program.

We will now run casing to protect the reservoir encountered in the well and look forward to coming back to test the well in accordance with previous environmental permit commitments to limit drilling and well testing during the period 1 October to 31 March. Environmental permitting for future operations will commence immediately. In between time there is much analysis work to do on the data recovered to date from drilling, coring and logging to commence the evaluation of the resource potential at Welchau. The intervening period gives us the time to plan a testing program with a smaller, lower-cost workover rig that is appropriate for running testing equipment in cased hole at Welchau, as well assessing the undrilled deeper potential that may be accessed from this well. In addition to Welchau, more detailed mapping will be undertaken on follow up structures already recognised within ADX' acreage.

For details please see the PDF file.

(Ende)