Pantheon Resources Issues Shareholder Letter and Provides Corporate Update on Dubhe-1

LONDON, GB - December 22, 2025 - Pantheon Resources plc (AIM:PANR) (OTCQX:PTHRF) ("Pantheon" or the "Company"), the oil and gas company developing the Kodiak and Ahpun oil fields near pipeline and transportation infrastructure on Alaska's North Slope, today issued a letter to shareholders from Pantheon Chairman David Hobbs.

Dear Shareholders,

As we move into 2026, I would like to thank our shareholders for their continued support, provide a recap of the milestones achieved, and discuss where we are headed in the year to come. Throughout 2025 we continued our work developing what we believe is America's next great oilfield on the Alaska North Slope with billions of barrels of resources, including accelerated appraisal efforts, and new leadership and capital to lead us forward.

During the year, we undertook the Dubhe-1 development demonstration to advance a capital efficient path toward commercialisation. While Dubhe-1 has not yet delivered the production outcome sought, the well generated valuable technical data and confirmed the presence of mobile hydrocarbons. Given the cost profile of winter operations and our focus on disciplined capital allocation, we have elected to pause testing at this time, a decision reflecting prudent financial management rather than diminished confidence in the asset. Supported by the capital raised during the year, Pantheon enters 2026 in a strong financial position, with flexibility to resume testing in the spring, assess additional interventions, and apply the insights gained to future development planning and farm-out discussions. The learnings from Dubhe-1 directly support our continued focus on advancing Kodiak, which remains the cornerstone of our portfolio and the primary driver of long-term shareholder value. As a reminder, Pantheon is leveraging distinct advantages with assets that are 100% located on state lands, adjacent to the Trans-Alaskan Pipeline (TAPS) and Dalton Highway, reducing development timeframe and cost with no expected environmental concerns. With a portfolio of high-impact oil projects spanning a 100% working interest across 258,000 acres, we currently hold independently certified best estimate contingent recoverable resources that currently total c. 1.6 billion barrels of ANS crude and 6.6 Tcf of associated natural gas across our properties. We continue to believe we are well positioned to develop our high impact U.S. oil projects on the Alaska North Slope.

Our commercial strategy established in 2023 was resource led and capital disciplined, focused on achieving sustainable market recognition exceeding $5 per barrel of independently certified 1P and 1C recoverable liquids. Kodiak represents a world class asset that anchors the portfolio, while Ahpun and other discovered resources provide nearer term development optionality due to their proximity to existing roads and pipelines. This infrastructure advantage materially reduces development costs and timelines, allowing activity to progress westward from existing infrastructure in a phased, capital efficient manner. We intend to prioritise projects capable of generating early free cash flow to support self-funded growth, minimising shareholder dilution while advancing Kodiak toward full development.

Evolving Leadership Team

Earlier this year we appointed Max Easley as Chief Executive Officer, bringing decades of appraisal and development experience in the oil and gas industry from firms such as BP, Apache and PETRONAS, with specific experience on Alaska's North Slope.  The mandate from the Board was to assess the quality of the assets with a view toward acceleration of development to maximise shareholder value.

We also welcomed Tralisa Maraj as Chief Financial Officer and Erich Krumanocker as Chief Development Officer. Tralisa has successfully led Pantheon's Finance team and recent financings with her more than 25 years of experience, including having previously been the CFO of two publicly listed companies. Erich has brought with him over 25 years of global experience in driving development, operations and project execution at scale across multiple continents.

Finally, Marty Rutherford joined us as a member of the Board of Directors, and we are benefiting from her more than 40 years of experience in policy roles, particularly her time in the State of Alaksa Department of Natural Resources shepherding Alaska's vast resources.

Dubhe-1 Operational Update

During the past 12 months, the Company took steps to re-align the management team to meet the challenges of more detailed reservoir appraisal and development planning.  This effort led to the decision to flow test the Ahpun reservoir in the South via this development demonstration well to determine the validity of foundational assumptions in the 2023 strategy. This is important because Ahpun is the key enabler in our 2023 strategy having successfully tested oil at Alkaid-2 in the North. Furthermore, hydrocarbon pay has been penetrated and logged at Pipeline State #1 and Talitha-A, all being located near key infrastructure. Ahpun has the potential for a capital efficient development and forward financing via free cash flow generation for Kodiak and other discovered resources.

The specific location of Dubhe-1 was chosen to balance the ability to reach it from a permanent surface location and test the lateral continuity of the reservoir. The targeted interval (SMD-B) had been penetrated multiple times and a pilot hole was drilled in advance of the lateral to ensure logged oil pay was present. The execution of Dubhe-1 represented a significant improvement in operating quality in a more capital efficient manner than previous wells.  

The well has now been cleaning up for nearly two months, during which time approximately 100,000 barrels of water, 20 million cubic feet of gas and 100 barrels of oil have been produced. ~200,000 barrels of stimulation fluids were injected into the well during the stimulation procedures, so ~50% has been recovered to date. The results to date suggest higher and/or more mobile water saturations than indicated in the historical and recent appraisal efforts. It is still too early to know whether this may be the result of the water introduced during the stimulation or be indicative of reservoir conditions. A longer flowback period, additional interventions and analyses may be required to better understand the reservoir mechanisms. 

There are no specific regional analogs for this reservoir fracture stimulated with a multitude of stages. But based on a number of consultation with industry peers, there is a wide range of possibilities and there are other conventional reservoirs of our type being commercially developed around the world that we believe have produced up to 100% of the injected stimulation fluids, and even beyond, prior to commercial quantities of oil. Whilst the SMD-B horizon at Alkaid-2 began to produce oil when approximately 50% of the injected stimulation fluids had been recovered, this outcome can vary widely amongst wells even in the same reservoir interval.  What is clear is that we have mobile hydrocarbons in this reservoir. Dubhe-1 has still recovered only ~50% of the stimulation fluids so far and based on analogs above we believe further cleanup is required before we can determine the commerciality of the well.

We believe the most financially prudent course of action is to pause testing in order to complete a planned pressure build-up test and other reservoir diagnostics on the well. In the meantime, we will reassess our operating cost base as winter flowback operations currently cost ~$150,000 per day. Given this, we will continue to evaluate data gathered from Dubhe-1 including analysis of the core and plan for testing and possible interventions and production re-start in the spring when we can ensure a more cost-effective way forward. Parallel analysis of the Kodiak field will be undertaken and an appraisal programme developed to accelerate progress irrespective of any outcome on this well.

While the results to date are not yet conclusive, ongoing analysis will help refine our strategy and strengthen our path to commercialisation, as well as confirm our approach of prioritising capital efficiency and technical rigor to maximise shareholder returns. This includes optimisation of stimulation, artificial lift techniques and a multitude of other factors.  We will build upon this and develop a clear pathway to maximise the value implicit in our asset base and ensure cost controls are in place, aligned to our activity set. Given all the factors above, we look forward to resuming production testing after the winter and will keep shareholders appraised of progress.

In coming months, the 2023 strategy will be tested and re-shaped by the new management team, inclusive of an updated reservoir and development outlook.

Kodiak - A World Class Oil & Gas Field

Our Kodiak project covers approximately 170,000 acres, partially underlying and immediately to the west of Ahpun. The field consists of a giant basin floor fan and was described by Wood Mackenzie in March 2023 as "the fourth biggest discovery well globally in 2022" and largest onshore. They have subsequently listed it as one of the top 20 oil discoveries of the 21st century. AHS Baker Hughes labelled it "a world class petroleum system" in summer of 2022.

We have successfully produced liquid hydrocarbons at both Talitha and Theta West located some 10 miles apart within the Kodiak acreage. There is significant volume upside to the Northwest of the area already penetrated, and based on regional trends, the quality of the reservoir is likely to improve in an updip location as well.  Independent experts Netherland, Sewell and Associates' best estimate for liquid hydrocarbon contingent resources is 1,208 million barrels, with an additional upside of ~600 million barrels of oil. Reprocessing of our seismic data will allow us to better define the top and base of the reservoir and predict internal architecture towards the edge of our leases and better image this upside potential. As part of this, we will begin planning for an appraisal well, possibly as early as next winter, and evaluating potential farm-out opportunities as they may arise.

We firmly believe that Kodiak is a world-class asset and is the centerpiece in our portfolio. It is also in an excellent location that will benefit from the infrastructure nearby. As we evaluate the most capital efficient and free cash flow generating path toward Kodiak development, we recognise that acceleration of its development will potentially add enormous shareholder value and underpin sustainable cash flow for decades to come.

Capital Resources Overview

As discussed previously, we had been making preparations for a potential listing on a U.S. exchange, should it be deemed the best path for shareholders in raising capital for development. To constrain expenditures, the activities had been restricted to re-examination of the Company's financial statements, confirming the optimum structure to avoid tax leakage, and designing internal controls that would serve investors regardless of whether a U.S. listing was progressed or not.  Whilst this is an option for the future, this effort remains paused until market conditions are such that this can be progressed.

As we exit 2025 and prepare for our 2026 activities discussed above, we believe we have benefitted greatly from our proactive management of our financial position. At 21 December 2025, unaudited cash, cash equivalents and term deposits totalled $27.2 million, prior to the settlement of the latest remaining Dubhe-1 related expenditures. These were anticipated and are fully incorporated into our capital planning assumptions. Following their settlement, the Company will continue to manage its liquidity position prudently, to provide flexibility to support technical work and the advancement of priority assets.

Moving forward, we intend to prioritise the financing of forward capital programmes by farming out to investment partner(s) to limit share dilution and add financial and capability resources to our expansive asset portfolio.

Looking Ahead & Final Thoughts

Looking ahead, we remain confident in the value inherent to our asset base, representing one of the largest undeveloped oil resources on the Alaskan North Slope. In our updated 2024 Independent Expert Report by Netherland Sewell & Associates, Inc., best estimates of Kodiak's contingent recoverable resources sum to 1.2 billion barrels of marketable liquids and 5.4 trillion cubic feet of gas. We are renewing focus on our Kodiak field, with a parallel analysis and appraisal programme developed to accelerate progress - all being done concurrent with additional testing and analysis of our data from Ahpun.

We thank you, our shareholders, for your support and we thank our employees for helping advance our development efforts. Our Annual Report and Accounts will be released this month with our AGM to occur in the first quarter of 2026. We therefore look forward to sharing future updates in the coming year as we strive to create value for our shareholders, employees, and communities, and we thank all of you for your dedication to our mission.

Sincerely,

David Hobbs
Chairman

For further information, please contact:

Corporate Contact
Pantheon Resources plc
Justin Hondris
contact@pantheonresources.com

Nominated Adviser and Joint Broker
Canaccord Genuity Limited
Henry Fitzgerald-O'Connor, James Asensio, Charlie Hammond
+44 20 7523 8000

Oak Securities - Joint Broker

Jerry Keen, Nick Pryce

+44 20 39733678

Public Relations Contact
BlytheRay
Tim Blythe, Megan Ray, Matthew Bowld
+44 20 7138 3204

Investor Relations Contact - USA
MZ Group
Lucas Zimmerman, Ian Scargill
+1 949 259 4987
PTHRF@mzgroup.us

In accordance with the AIM Rules - Note for Mining and Oil & Gas Companies - June 2009, the information contained in this announcement has been reviewed and signed off by David Hobbs, a qualified Petroleum Engineer and a member of the Society of Petroleum Engineers, who has 40 years' relevant experience within the sector. 

The information contained within this Announcement is deemed by Pantheon Resources PLC to constitute inside information as stipulated under the Market Abuse Regulation (EU) No. 596/2014 as it forms part of UK law by virtue of the European Union (Withdrawal) Act 2018 ("MAR").

About Pantheon Resources

Pantheon Resources plc is an AIM listed Oil & Gas company focused on developing its 100% owned Ahpun and Kodiak fields located on State of Alaska land on the North Slope, onshore USA. Independently certified best estimate contingent recoverable resources attributable to these projects currently total c. 1.6 billion barrels of ANS crude and 6.6 Tcf of associated natural gas. The Company owns 100% working interest in c. 259,000 acres.

Pantheon's stated objective is to demonstrate sustainable market recognition of a value of approximately $5 recoverable resources by end 2028. This is based on bringing the Ahpun field forward to FID and producing into the TAPS main oil line (ANS crude) by the end of 2028. The Gas Sales Precedent Agreement signed with AGDC provides the potential for Pantheon's natural gas to be produced into the proposed 807 mile pipeline from the North Slope to Southcentral Alaska during 2029. Once the Company achieves financial self-sufficiency, it will apply the resultant cashflows to support the FID on the Kodiak field planned, subject to regulatory approvals, targeted by the end of 2028 or early 2029.

A major differentiator to other ANS projects is the close proximity to existing roads and pipelines which offers a significant competitive advantage to Pantheon, allowing for shorter development timeframes, materially lower infrastructure costs and the ability to support the development with a significantly lower pre-cashflow funding requirement than is typical in Alaska. Furthermore, the low CO2 content of the associated gas allows export into the planned natural gas pipeline from the North Slope to Southcentral Alaska without significant pre-treatment.

The Company's project portfolio has been endorsed by world renowned experts. Netherland, Sewell & Associates estimate a 2C contingent recoverable resource in the Kodiak project that total 1,208 mmbbl of ANS crude and 5,396 bcf of natural gas. Cawley Gillespie & Associates estimate 2C contingent recoverable resources for Ahpun's western topset horizons at 282 mmbbl of ANS crude and 803 bcf of natural gas. Lee Keeling & Associates estimated possible reserves and 2C contingent recoverable resources totalling 79 mmbbl of ANS crude and 424 bcf natural gas.

For more information visit www.pantheonresources.com.