Kodiak resource upgraded to 1.2 billion barrels

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, is pleased to share the results of the updated Independent Expert Report ("IER") by Netherland Sewell & Associates, Inc. ("NSAI"). This update includes approximately 43,000 acres of the leases on which the Company was the successful bidder in December 20231, located on its 100% owned Kodiak Field on the North Slope of Alaska.

Highlights

• NSAI's best estimates of Kodiak's contingent recoverable resources sum to 1.2 billion barrels of marketable liquids (oil, condensate and natural gas liquids) and 5.4 trillion cubic feet of gas ("tcf").
• The new resource represents a 25% increase (963 to 1,208 million barrels ("mmbbls")) in recoverable marketable liquids compared to NSAI's previous 2023 report.
• The updated numbers include c. 43,000 of the c. 66,000 acres of the expanded acreage footprint post the successful lease bids in December 20231, and a higher average recovery rate due to the better reservoir properties in the shallower, updip portion of the field secured by the new leases.
• Kodiak is a large basin floor fan accumulation with three well penetrations. Recent drilling activity and acreage acquisition strategy has focused on moving structurally higher into better reservoir rocks where porosity and permeability are substantially improved.
• The potential improvement in reservoir quality in the newly acquired acreage underpins the c. 40% increase in the high estimate of recoverable resources to 2,840 mmbbls of marketable liquids and 11.75 tcf of natural gas.
• The 5.4 tcf of recoverable gas (Best Case) is important as additional support for a proposed agreement with Alaska Gasline Development Corp ("AGDC") to bring gas to southcentral Alaska markets.

NSAI Contingent Resource estimate

Gross 100% Working Interest Contingent Resources

The Kodiak oil and gas field currently represents Pantheon's largest project development candidate, currently defined by three well penetrations into the Basin Floor Fan structure, which extends more than 10 miles from the deepest part of the fan to the 2021 updip Theta West-1 appraisal well. The additional recent successful lease bids secure the remainder of the accumulation to the northwest and adds a significant volume of recoverable oil and gas to the Kodiak field. Pantheon has been able to delineate the full extent of the field through its proprietary 3D seismic where seismic attributes have clearly indicated the presence of light oil across the entirety of the field.

NSAI estimated an increased average recovery factor of 8% across the field for liquids due to expectations of substantially improved porosity and permeability in the northwest, updip portion of the field. Recovery factors for gas are in the range of 30-40%, based on primary recovery only. Pantheon believes these recovery factors may increase further once supported by drilling data in the northwest portion of the acreage.

The updip extensions of the Kodiak field are more analogous to producing fields, including Tarn and Meltwater. Future appraisal drilling will focus on the shallower, better quality reservoir sections to demonstrate the validity of increased recovery factors and production performance.

The NSAI updated report on Kodiak is one of several IERs being prepared for Pantheon as it progresses funding options for its projects. To expedite a more rapid completion of these reports, Pantheon commissioned IERs for (the shallower) Ahpun Topsets and (the deeper) Alkaid Zone from Cawley Gillespie & Associates ("CGA") and Lee Keeling & Associates ("LKA") respectively. These reports are expected over the next month and are integral to financing discussions.

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

The NSAI report can be found at www.pantheonresources.com

Pantheon will be hosting an Investor Meet Company webinar at 5.00pm BST on Wednesday April 10th. Those wishing to participate can register through the following link:

David Hobbs, Executive Chairman of Pantheon Resources, commented:

"The underpinning of our strategy with the validation provided by NSAI is an important step on the path to our 2028 goal of demonstrating values in the range $5-$10 per barrel of recoverable resource. Recent progress towards securing funding, include leveraging our natural gas resources - potentially turning them from a liability to an asset - allows us to move forward with increased confidence. I would like to take the opportunity to congratulate Jay and his team on putting the building blocks in place to deliver our ultimate success."

Bob Rosenthal, Technical Director of Pantheon commented:

"This NSAI report reveals the true scale of the Kodiak Field now that we have secured leases over its full extent. The potential upside is vast - NSAI recognise a high estimate in excess of 2.8 billion barrels of recoverable marketable liquids and nearly 12 trillion cubic feet of recoverable natural gas. As we drill wells and obtain additional data, our goal is to progressively move the 'best case estimate' towards NSAI's 'high case estimate' over time.

"Discovering a billion-barrel oil accumulation is what companies dream about and the Independent Expert Report by NSAI validates our Company's significant achievements over the past decade. We can now turn our attention to development, along with our growing Ahpun resource, to turn these volumes to cashflow and value for shareholders."

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 nearly 40 years' relevant experience within the sector.

The estimates in the Kodiak NSAI IER 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).

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").

Glossary

Bbls: barrels

Contingent Resource: Those quantities of petroleum estimated, as of a given date, to be potentially recoverable from known accumulations by application of development projects, but which are not currently considered to be commercially recoverable owing to one or more contingencies.

For Contingent Resources, the general cumulative terms low/best/high estimates are used to estimate the resulting 1C/2C/3C quantities, respectively. The terms C1, C2, and C3 are defined for incremental quantities of Contingent Resources:

• C1: Denotes low estimate of Contingent Resources. C1 is equal to 1C.
• C2: Denotes Contingent Resources of same technical confidence as Probable, but not commercially matured to Reserves.
• C3: Denotes Contingent Resources of same technical confidence as Possible, but not commercially matured to Reserves.

When the range of uncertainty is represented by a probability distribution, a low, best, and high estimate shall be provided such that:

• There should be at least a 90% probability (P90) that the quantities actually recovered will equal or exceed the low estimate.
• There should be at least a 50% probability (P50) that the quantities actually recovered will equal or exceed the best estimate.
• There should be at least a 10% probability (P10) that the quantities actually recovered will equal or exceed the high estimate.

The project maturity subclass for these contingent resources is development unclarified.

Development Unclarified is a discovered accumulation where project activities are under evaluation and where justification as a commercial development is unknown based on available information.

NGLs: Natural gas liquids (NGL) are components of natural gas that are separated from the gas state in the form of liquids.

Overriding Royalty Interest (ORRI): A royalty granted to a third party other than the royalty payable to the State of Alaska.

Working Interest: The legal ownership of the leases awarded by the State of Alaska. Pantheon's Net Revenue Interest (NRI) in the leases is less than 100% by virtue of royalties payable to the State and any ORRI. In the case of the Kodiak project, the State royalties vary between 12.5% and 16.67%. Management estimates that the average NRI is approximately 85%.