The Anshof-3 well and early production unit. (Credit: © ADX Energy Ltd.)
Map showing the ADX-AT-II exploration license, the Anshof (ANS) oil field and near field prospects in yellow. (Credit: © ADX Energy Ltd.)
As of August 2023, the Anshof-3 well was producing around 120 barrels of oil per day (bopd). (Credit: Anita starzycka from Pixabay)

Anshof is an onshore oil field located within the ADX-AT-II exploration licence area in the Molasse Basin, Austria.

Australian Stock Exchange (ASX)-listed and European focussed oil and gas company ADX Energy (ADX) is the operator of the field.

A long-term crude oil production test from the Anshof-3 discovery well began in October 2022.

Austria’s Ministry of Finance awarded a production licence to ADX’s wholly owned subsidiary ADX VIE for the development Anshof oil field in March 2023.

As of August 2023, the Anshof-3 well was producing around 120 barrels of oil per day (bopd) with no water production and minor pressure decline.

Ownership Details

In November 2020, ADX finalised agreements with the Austrian Mining Authority securing exploration and appraisal licences in the Molasse basin in Upper Austria surrounding RAG Austria (RAG) producing fields and infrastructure.

In November 2021, ADX signed a farm-in agreement with Xstate Resources to fund drilling activity at the Anshof. As per the agreement, Xstate funded 40% of the Anshof well drilling expenditure up to €1.8m to secure a 20% economic interest in the prospect area.

MND Austria signed an Energy Investment Agreement (EIA) with ADX VIE in August 2023 to earn a 30% economic interest in the Anshof Field Area by investing up to €11.52m. The deal closed in September 2023.

ADX now operates Anshof field with 50% economic interest in the Anshof Field Area. MND Austria and Xstate Resources are the other stakeholders with 30% and 20% interests respectively.

ADX continues to own a 100% interest in the remaining ADX-AT-II exploration area other than the Welchau Area where it holds an 80% economic interest.

The company also has 100% stake in adjacent oil prospects such as GRB.

Anshof Field Discovery

ADX received final environmental authority approvals and commenced site works for the drilling of the Anshof prospect in November 2021. The company also received approval from the Austrian Mining Authority to drill up to three wells from the Anshof-1 well site in the same month.

In December 2021, Anshof-3 well was spudded by RED Drilling & Services’ E-200 rig. The well encountered shallow gas from approximately 175m onwards.

The well was drilled, evaluated and cased in January 2022.

Commercial crude oil production from the Eocene oil reservoirs using the Anshof-3 well began in October 2022.

Geology and Reserves

Before the discovery, Anshof was defined as a well-defined modern 3D seismic covered Eocene – Cenomanian prospect located up-dip and on-trend from existing oil production from adjacent fields.

The Eocene oil produced from the field is a high quality (33° API) crude with low sulphur content.

According to an independent assessment, the Anshof field contains estimated 2P (proven + probable) reserves of 5.2 million barrels of oil equivalent as of October 2022.

The Net Present Value (NPV8) of the gross 2P reserves is around €42.3m.

The Independent Assessment also noted that the field’s large 3P (proven + probable + possible) reserves and 3C contingent resource potential of 26 million barrels of oil equivalent. This is planned to be appraised with additional drilling.

Anshof Field Operations

ADX has leased an early production unit (EPU) production system to pre-process, store and remotely monitor operations.

The unit includes facilities for oil and gas separation, power generation, well site storage, offloading and telemetry control systems at the Anshof-3 well location.

The deployment of EPU enables oil production with minimal operator intervention.

After initial processing, the oil is transported by truck to a nearby oil terminal for final processing and then it is delivered to the OMV refinery near Vienna for sale.

The company intends to utilise the EPU until permanent facilities are developed.

ADX plans to drill Anshof-2 and the Anshof-1 wells from the same drilling and production site as the Anshof-3 well.

These two wells will target thicker reservoir intersections on the 25km2 mapped Anshof structure.

Anshof-2 appraisal and development well is expected to be drilled in the fourth quarter of 2023, while Anshof-1 is scheduled for 2024.

The three wells, together, are expected to produce 750 to 1,000 bopd.

Contractors Involved

ADX Energy engaged RED Drilling & Services for drilling operations. The Anshof-3 well was spud using the RED E-200 drilling rig.

In October 2022, RISC Advisory (RISC) completed an independent audit of reserves and resources for the oil field. The report encompasses production forecasts, cost estimates, project economics and valuations of reserves by category for the Eocene reservoirs.