United Oil & Gas PLC / Index: AIM / Epic: UOG / Sector: Oil & Gas

25^th September 2025

United Oil & Gas plc

("United" or "the Company")

Independent Risking Study Confirms Derisking Potential from

Geochemical Work at Walton-Morant

United Oil & Gas Plc (AIM: "UOG"), the oil and gas company with a high impact exploration asset in Jamaica and a development asset in the UK, is pleased to announce the findings of an independent Risking Review Study by Iapetus Geoscience Limited (the "Study") that highlights the value of the planned Surface Geochemical Exploration ("SGE") survey, including piston coring, at the Walton Morant Licence offshore Jamaica.

This Study provides compelling evidence that the SGE survey could materially de-risk the Walton Morant Licence. A successful piston coring programme could significantly increase the Geological Chance of Success ("GCoS") across multiple high-impact prospects and leads by validating the presence of an active petroleum system in the licence area.

Key Findings: Material Risk Reduction from Future Piston Coring Results

The summary conclusion is that successful piston coring would:

§ Increase the GCoS at Colibri prospect to 32% - uplifting from the previous 19% estimate (GaffneyCline, 2020)¹

§ Raise the GCoS at the Oriole prospect to 21% from 13% (GaffneyCline 2020) ¹

§ Confirm that a working petroleum system exists offshore Jamaica that is already verified onshore

§ Similar uplift in GCoS would be anticipated across the prospectivity of the broader Walton and Morant basins

These outcomes would substantially improve pre-drill confidence and de-risk the licence at scale. The full Risking Review Study report is available on United's website.

Importantly, the independent review itself strengthens the technical case for Walton Morant, enhancing its attractiveness to potential farm-in partners. The uplift scenarios highlight how future technical work can further de-risk the basin, supporting United's strategy of continuous technical de-risking to underpin commercial engagement.

Brian Larkin, CEO of United Oil & Gas, commented:

"We are very encouraged by the findings of this independent study, which reinforces our belief that our Jamaican licence is a world-class yet underexplored opportunity.

A 1-in-3 Geological Chance of Success at Colibri would be exceptional for frontier exploration, with the uplift indicative of broader basin potential. Even at this stage, the independent review itself enhances the technical case for Walton Morant and increases its appeal to potential farm-in partners.

Interest from potential farm-in partners continues, supported by Walton Morant's multiple drill-ready prospects with an estimated 7.1 billion barrel of potential². Alongside recent permitting progress, this independent validation underscores both the technical momentum and enormous commercial opportunity as we advance farm-out discussions and preparations for future activity."

About the Study

The review assessed the current GCoS at the Colibri and Oriole prospects and modelled how surface geochemical exploration, particularly piston coring, could enhance those chances. Uplift would come from detecting thermogenic hydrocarbons in seabed samples, thus providing direct evidence of an active source rock and effective migration pathways within the licence area.

The planned SGE work involves collecting 40-60 piston core samples, supported by high-resolution multibeam echosounder (MBES) mapping of the seabed. Additional heat probe data acquisition will also help to refine basin modelling.

The study was commissioned from Iapetus Geoscience Limited, an independent geoscience consultancy with more than 35 years' experience in petroleum exploration, basin risking and geochemical analysis projects for NOCs, IOCs and supermajors in both frontier and mature regions worldwide.

Qualified Person Statement

Paul Ryan, Geoscience Advisor to UOG, who has over 20 years of relevant experience in the oil and gas industry, has reviewed and approved the information contained in this announcement.  Paul Ryan is a qualified person as defined in the guidance note for Mining Oil & Gas Companies of the London Stock Exchange and is a member of the Geoscience Exploration Society of Great Britain (GESGB), the American Association of Petroleum Geologists (AAPG) and the Society of Petroleum Engineers (SPE). 

Disclaimer

Risking is an imprecise science open to a range of subjectivities and psychological biases (Polson and Curtis, 2010). There is no "standard" approach within the industry and no widely accepted benchmarking. There is also no "correct" answer. A drilled prospect will either be a discovery (Pg = 1.0) or a failure (Pg = 0.0). Risking is the best attempt to summarise all the available evidence and understanding of an exploration play or prospect to estimate chance of geological success in a probabilistic manner. Most approaches estimate a probability for each of the independent fundamental components in the petroleum system and multiply these together to give an overall Pg (e.g. Rose, 2001). The definition and number of the components vary between operators, but they are always weighted equally because the failure of any one of them results in a failure of the prospect.

Iapetus Geoscience Limited is an independent consultancy that has no commercial interest in the Walton-Morant Licence, and it has carried out the risking as objectively as possible.

1.   Prospective Resources Report by Gaffney Cline & Associates (GaffneyCline), December 2020.

2.   Based on UOG's arithmetic sum of the Unrisked Mean or Mid-Case Prospective Resources for each prospect or lead identified within the Walton Morant Licence boundary by UOG and/or previous operators

**ENDS**

Beaumont Cornish Limited ("Beaumont Cornish") is the Company's Nominated Adviser and is authorised and regulated by the FCA. Beaumont Cornish's responsibilities as the Company's Nominated Adviser, including a responsibility to advise and guide the Company on its responsibilities under the AIM Rules for Companies and AIM Rules for Nominated Advisers, are owed solely to the London Stock Exchange. Beaumont Cornish is not acting for and will not be responsible to any other persons for providing protections afforded to customers of Beaumont Cornish nor for advising them in relation to the proposed arrangements described in this announcement or any matter referred to in it.

Notes to Editors

United Oil & Gas is an oil and gas company with a development asset in the UK and a high impact exploration licence in Jamaica.

The business is led by an experienced management team with a strong track record of growing full cycle businesses, partnered with established industry players and is well positioned to deliver future growth through portfolio optimisation and targeted acquisitions.

United Oil & Gas is listed on the AIM market of the London Stock Exchange. For further information on United Oil and Gas please visit www.uogplc.com