Prospex Energy PLC / Index: AIM / Epic: PXEN / Sector: Oil and Gas

20 November 2025

Prospex Energy PLC

("Prospex" or the "Company")

Viura Operational Update

Prospex Energy PLC (AIM: PXEN), the AIM quoted investment company focused on European gas and power projects, is pleased to provide an operational update on the Viura field in northern Spain.  The operator of the Viura field is HEYCO Energía Iberia S.L. ("HEI").

Prospex owns 7.24% of the Viura field through its ownership of 7.5% of HEI.  Prospex is accruing 14.47% of the production income from the Viura gas field until payback of its initial capital investment (expected to be ≈£8 million) plus the accrued 10% p.a. interest thereon.

Viura Operational Highlights

·    Steady production from the Viura Well at a gross plateau rate averaging more than 190,000 scm/d (≈6.6 MMscfd) in line with expectations.

·    Average production rate net to Prospex at 14.47% is more than 27,100 scm/d (≈1 MMscfd).

·    Water production has reduced to an average of less than 10 cubic metres per day which equates to an average of ≈9 Bbls/MMscf.  This improved performance is a direct result of the new completion installed earlier in the year.

·    The operator is working on the reprocessed 3D seismic database with a view to optimising the structural model so that a reserve report can be commissioned to support a debt facility to fund the development wells now scheduled in late 2026 or early 2027.

Mark Routh, Prospex's CEO, commented:

"I am pleased to report that after a month of gas production from bringing the Viura-1B well back online on 17 October 2025, the well is producing gas at a steady plateau rate of more than 190,000 scm/d with a reduced water cut on account of the newly installed well completion.  This confirms our long-held view that the Viura field is a strongly performing asset and that the recent production outage was an anomaly.

"Subsurface studies are ongoing with the objective to independently verify the gas reserves in the Viura field to support a debt facility for future funding of the development wells.  Further months of production at this stabilised plateau rate will further enhance viability of an independent reserves report."

This announcement contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ("MAR") and is disclosed in accordance with the Company's obligations under Article 17 of MAR.

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For further information visit www.prospex.energy or contact the following:

Background

The Viura acquisition significantly increased Prospex's estimated reserves by 6.5 Bcf (0.18 Bcm) net to Prospex.  The Operator's best estimate of recoverable gross remaining reserves at the Viura field is 90 Bcf (2.5 Bcm) and is expected to increase upon further evaluation of the newly drilled horizons.  Once the newly reprocessed 3D seismic is reinterpreted it is the Operator's intention to update the reservoir model, gas in place and obtain an independently verified report on the reserves for the Viura field.

Glossary:

Bbl                          Barrel (≈5.615 scf or ≈0.158987 scm)

Bcf                          Billion standard cubic feet

Bcm                       Billon standard cubic metres

MMscfd                million standard cubic feet per day

MMscm                Million standard cubic metres

MWh                     Mega Watt hour

scf                          Standard cubic feet

scm                        Standard cubic metres

scm/d                   Standard cubic metres per day

TTF                         The 'Title Transfer Facility' - a virtual trading point for natural gas in the Netherlands

Qualified Person Signoff

In accordance with the AIM notice for Mining and Oil and Gas Companies, the Company discloses that Mark Routh, the CEO and a director of Prospex Energy plc has reviewed the technical information contained herein.  Mark Routh has an MSc in Petroleum Engineering and has been a member of the Society of Petroleum Engineers since 1985.  He has over 40 years operating experience in the upstream oil and gas industry.  Mark Routh consents to the inclusion of the information in the form and context in which it appears.