Operational Update - Dubhe-1

2 December 2025

Pantheon Resources plc

Operational Update - Dubhe-1

Pantheon Resources plc (AIM: PANR, OTCQX: PTHRF) ("Pantheon" or the "Company"), the oil and gas company developing the Kodiak and Ahpun oil fields immediately adjacent to pipeline and transportation infrastructure on Alaska's North Slope, is providing an operational and cost update on the Dubhe-1 well.

Operational Update

Well clean-up operations at Dubhe-1 are progressing with production dominated by previously injected stimulation fluids. Intermittent oil production from Dubhe-1 commenced on 3rd November, and consistent small oil volumes commenced from around 19th November. Gas production volumes increased throughout this period. Thus far, approximately 40% of the injected water volume has been produced with steady gas production along with the modest production of light oil. The Company's closest analog to this well is the SMD-B interval in Alkaid-2 which was flow tested in 2023 and first measured oil production when a water volume equivalent to approximately 50% of the injected water volume had been produced. The Company plans to continue the well clean-up until a representative oil flow rate can be determined. Given that Dubhe-1 has multiple fracked stages, the clean-up profile may differ from the previous single zone completion as each stage may clean up at different points in time.

In May 2025, the Company expected that the cost for Dubhe-1 would be consistent with historical costs of approximately c.$10 million for drilling the well with a +/-5000 ft lateral/horizontal and approximately $15 million for the well completion. During final well planning and data gathering decisions, the Company chose to drill a pilot hole to allow core samples to be collected, to better refine the target landing zone and to penetrate the deeper Slope Fan System (SFS) as well as the shallower SMD-C reservoir target. The final cost for drilling and completing was approximately $33 million, including the pilot hole to enable evaluation of shallower and deeper horizons and acquisition of whole and sidewall cores.

Overall, this cost outcome, inclusive of full appraisal scope, contingency measures (e.g. standby drilling rig and coil tubing unit based on the experience at Alkaid-2), and inflationary pressures, does not detract from a solid operating performance. In addition, the construction of the new Dubhe pad, which will also be available for the drilling of future wells, cost $2.5 million. Clean-up, flow-back and well testing operational costs will be determined at the end of the programme.

Max Easley, Chief Executive Officer, commented: "I continue to be pleased with the ongoing safe and efficient execution of our operations to date and look forward to sharing more about Dubhe-1 results when we have them."

Further information:

 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 per barrel of 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 of 79 mmbbl of ANS crude and 424 bcf natural gas.

For more information visit www.pantheonresources.com.