Webinar and update

Pantheon Resources plc (AIM: PANR) ("Pantheon" or "the Company"), the oil and gas company with a 100% working interest in the Kodiak and Ahpun projects, covered by 193,000 acres of leases with an additional c. 66,000 acres to be awarded following successful bids in the December 2023 lease sales, all in close proximity to pipeline and transportation infrastructure on Alaska's North Slope, confirms that as previously announced, a webinar presentation and Q&A will be held at 5.00pm British Summer Time today and is open to all shareholders and other interested parties (the "Webinar"). Registration details can be accessed at: https://www.investormeetcompany.com/pantheon-resources-plc/register-investor

A copy of the PowerPoint presentation to be delivered during the Webinar and a recording of the webinar will be uploaded to the Company's website at https://www.pantheonresources.com/ once available.

About the Webinar

In this Webinar, the management team will provide further context on the newly released Independent Expert Report ("IER") on the Kodiak Field by Netherland, Sewell & Associates ("NSAI"), Pantheon's newly released management resource estimate on the new leases for the Eastern extension of the Ahpun field, modelled individual well economics, together with a detailed Q&A session. The presentation will address the following, including certain updated information:

• NSAI Report Summary and Appraisal Upside
• Additional IERs presently underway on Ahpun
• Modelled Individual well economics and commerciality
• Pantheon management resource estimates - Ahpun project - Eastern Topsets
• Discussion on opportunity for non-equity dilutive funding backed by potential gas sales to in-state consumers through the AGDC proposed gas pipeline
• Discussion on potential Helium opportunity
• Q&A

Current Resource Base for Pantheon Leases in ANS (based upon 100% working interest)

NSAI Contingent Resource Estimates - Kodiak Field

Following receipt of NSAI's Independent Expert's Report announced on 9 April 2024, the current best estimate of contingent recoverable marketable liquids stands at 1,207.9 million barrels ("mmbbls") and 5,396.3 billion cubic feet ("bcf") of natural gas for the Kodiak Field. This represents a 25% increase compared to the 2023 assessment prior to the inclusion of the new leases on which Pantheon was the successful bidder in December 2023. The high estimate shows a better than 40% increase on the previous report, reflecting the potential for substantial improvement in reservoir properties at shallower depths in the new leases.

Lee Keeling & Associates ("LKA") Reserves Estimates - Ahpun Field, Alkaid Horizon

LKA has been contracted to provide an updated Independent Expert Report ("IER") on the Alkaid horizon of the Ahpun Field. This work is presently underway and will be released once completed.

Cawley Gillespie & Associates ("CGA") Contingent Resource Estimates - Ahpun Field, Western Topsets

CGA has been contracted to provide an IER on the Western Topsets in the Ahpun Field. This work is presently underway and will be released once completed.

Management Resource estimate - Ahpun Eastern Topsets

Approximately 23,000 of the c.66,000 acres successfully bid for in December 20231 cover the Eastern Topsets of the Ahpun project. Management has completed an internal resource assessment and, in a P50 case, estimates a Prospective Resource (gross) of 609 million barrels of marketable liquids, as summarised in the table below. The Company intends to drill an exploration/appraisal well in the Ahpun Eastern Topset, once funded, to further refine the resource estimate.

1 The Company has paid an initial 20% deposit to the State of Alaska with the remainder payable on official award of the new leases which is anticipated this quarter.

Ahpun Eastern Topsets - Management resource estimate - 100% working Interest1

• Gross resources - prior to deduction of c. [13.5% to 17.7%] royalties.
• Pantheon will have 100% working interest in all leases once award complete.
• Management resource estimates have been prepared in accordance with definitions and guidelines set forth in the 2018 Petroleum Resource Management System (PRMS) approved by the Society of Petroleum Engineers (SPE).
• Estimated 70% Geological probability of success.

SLB Modelling Update - Ahpun Western Topsets Individual Well Type Curve

SLB has continued its dynamic modelling of Pantheon's reservoirs and provided a single well model based on the rock properties logged and sampled (whole core) at the Pipeline State-1 well location. This results in per well recoveries of 3.7 million barrels of marketable liquids and 8 bcf of natural gas.

Illustrative Economic Modelling - Ahpun Western Topsets Individual Well Company Assessment

SLB's results are consistent with the Company's own modelling, which estimates 3.5 mmbbls and 8 bcf expected recoveries per well, and yields the following economic results (on a pre-Federal Income Tax basis):

Illustrative examples - Per well modelled economics

Ahpun Topsets EUR 3.5 mmbbls

Principal assumptions and management estimates:

• ANS prices have been discounted by 10%.
• Wells modelled at 3.5 million bbl marketable liquids EUR in Ahpun Topsets, 3.65 million bbl in Kodiak at Theta West-1 location and 4.56 million bbl in updip Kodiak locations.
• Assumed zero revenues for natural gas or helium.
• Transportation costs - TAPS tariff and shipping to US West Coast estimated at $7.50/bbl.
• 1 injection well modelled for every 3 production wells.
• Production wells costed at $17 million and injection wells costed at $15 million per well.
• Well pads and production facilities estimated at $50 million for 20 well pad.
• State profits tax at 35% after payout (4% minimum tax rate prior to payout). Pre federal taxes.
• Estimates based upon information available at the date of announcement - actual outcomes may differ.

Glossary

Bbls: barrels

Bcf: Billion cubic feet

Prospective Resources: Those quantities of petroleum which are estimated, on a given date, to be potentially recoverable from undiscovered accumulations.