Zephyr Energy Regulatory News (ZPHR)

Prior to publication, the information contained within this announcement was deemed by the Company to constitute inside information as stipulated under the UK Market Abuse Regulation. With the publication of this announcement, this information is now considered to be in the public domain.

29 May 2025

Zephyr Energy plc

(the "Company" or "Zephyr")

Operations Update

Initial results from State 36-2R well evaluation

 Williston Project and Zephyr Hawk update

Zephyr Energy plc (AIM: ZPHR) (OTCQB: ZPHRF) is pleased to provide initial post-well evaluation results from the State 36-2R LNW-CC-R well (the "State 36-2R well") at the Company's flagship project in the Paradox Basin, Utah, U.S. (the "Paradox project"). In addition, the Company also provides initial results related to hydrocarbon production in the first quarter of 2025 ("Q1") from its non-operated asset portfolio in the Williston Basin, North Dakota and Montana, U.S. (the "Williston project") as well as an update on business development activities in relation to the Williston project.

Colin Harrington, Zephyr's Chief Executive, said:

"The quality of the data gathered from our recent production test on the State 36-2R well is solid, and the results are robust. The evaluation confirms that the Cane Creek reservoir is highly productive and potentially ranks alongside some of the most productive oil and gas plays in the U.S. The results also suggest that there may be a substantial increase in our base case recoverable resources which could add tremendous value to the project over time.

"The decision to perform a novel perforation and acidisation completion has been very much vindicated, and the potential for further optimisation of the project is exciting. Our operations team, alongside key service company partners, did an excellent job in delivering this result and I am thrilled with these initial findings.

"There is much still to do, and our team is hard at to work to deliver on our next key objective of delivering first gas.

"While the results announced today focus solely on the Cane Creek reservoir, it should be remembered that there are eight other overlying reservoir zones with core data that compares well with the Cane Creek B reservoir zone. This highlights the further substantial potential of our project acreage that is yet to be tested. The scale of the project has the potential to grow considerably and we look forward to sharing further information with both the market and potential partners as work continues.

"I am also pleased to be able to announce our initial Q1 results from the Williston project which continues to perform as a cash generating engine for the wider group. Work at our Zephyr Hawk subsidiary has also commenced with a strong level of initial deal flow being evaluated."

State 36-2R well evaluation

The Zephyr team has conducted an integrated post well evaluation incorporating all geological, geophysical and engineering data gathered from the State 36-2R well and from the greater field area. The key results from the evaluation are set out below.

· Management estimates of gas estimated ultimate recovery (EUR) for the State 36-2R well range from 4-6 billion cubic feet ("BCF") (0.9 to 1.3 BCF/1000 feet (') of perforated interval) and between 160,000 and 240,000 barrels of condensate, equivalent to a total range of 0.827 to 1.24 million barrels of oil equivalent ("boe") for the well. The internal technical evaluation of this well is now largely complete, prior to further review by a third party.

· These results can be scaled to longer lateral lengths (e.g. 10,000' to 15,000' laterals) for the purpose of field development planning, with potential gas EURs ranging from 9 to 37.5 BCF per well (dependent upon completed lateral length, location on structure, expected reservoir and fluid properties). Although well lengths will be constrained by the structural form of the reservoir, as observed from the 3D seismic data and by the overall well bore geometry proposed, the proposed conceptual development wells consist of predominantly 10,000 feet to 15,000-feet horizontal wells. While drilling and completing longer horizontal wells has not been undertaken in the Paradox previously, the use of longer 2 and 3 mile laterals is widespread in other U.S. resource plays and extends to 4 mile laterals in some locations.

· The overall liquid yield development over the life of the well is expected to deliver valuable condensate volumes ranging between 60-130bc/mmscf (barrels of condensate per million standard cubic feet of gas) at initial reservoir conditions. Over the estimated 20-year life of the well, total liquid yield estimates of 20-60bc/mmscf are expected as reservoir pressure drops.

The estimated normalised gas EUR/1000' lateral length forecast for the 36-2R well (0.8-1.3 BCF/1000') and across the greater development area (0.8-2.5 BCF/1000') suggest potential well performance that is comparable to the top six per cent of hydraulically stimulated horizontal gas wells across all the key lower 48 onshore US plays, based on production, well data and EUR assessment from the Enverus Prism database.*

· These single well assessments can also be applied to a conceptual full field development plan to understand the larger potential resource range of the Cane Creek reservoir with 3D seismic coverage and which is under lease by Zephyr. This conceptual development plan suggests the potential for a further 20 Cane Creek reservoir horizontal wells (plus the previously drilled State 16-2 LN-CC and State 36-2 wells), with preliminary management estimates of gross ultimate recoverable gas in a low-mid-high scenario range of 174 - 341 - 501 BCF and 3.5 - 15.7 - 29mmbc of recoverable condensate (and set out in the table below).

· Initial management estimates of net ultimate recoverable resources range from 137 - 271 - 399 BCF and 2.7-12.5-23.1 mmbc (26-58-90 mmboe net recoverable resources) (and are set out in the table below). These estimates are interim and have been developed solely to illustrate the potential recoverable resource of the Cane Creek reservoir under lease. Further field development planning work and economic analysis will be completed prior to the completion of a revised Competent Persons Report on the Paradox project.

​

Further observations on the State 36-2R well include the following:

The well is producing along the entire length and from all three reservoir zones of the Cane Creek reservoir, and predominantly from the Cane Creek B reservoir zone. This is due to the fact that the well was mostly drilled and completed in the Cane Creek B reservoir zone. The near wellbore area shows increased permeability that is most likely caused by the successful acid stimulation. The well was not hydraulically fractured during perforation or acidisation.

The reservoir matrix permeability also appears to be as good, or better, than the Company's pre-drill, base case estimate of reservoir permeability, a key driver for the estimated improvement in the resource base.

The novel completion technology deployed has been very successful both in terms of accessing the reservoir but also enabling the assessment of the matrix permeability and potential exists to further improve completion effectiveness during future development.

Reservoir properties were determined from the well test results using an analytical model. The resulting properties were then used to build a numerical model to generate production forecasts. Both models were consistent with the geological interpretation of the well and regional geologic data gathered previously.

*Sample size used is the top 6,900 wells out of a total of 116,000 gas wells, as defined by Enverus.

** Estimated Ultimate Recovery has no economic limit applied and is used here to illustrate the technical potential of the well and field area.

Williston Project and Zephyr Hawk update

The Company also reports initial Q1 results related to hydrocarbon production from the Company's Williston project.

· Q1 production averaged 756 boepd, net to Zephyr, versus an average production in the fourth quarter of 2024 ("Q4") of 829 boepd, net to Zephyr. Both Q4 and Q1 were impacted by operator induced downtime, and the Company expects the production impacts to be temporary.

· At 31 March 2025, 228 wells in Zephyr's portfolio were available for production (versus 229 wells at the end of Q4).

· Net working interests across the Zephyr portfolio now average 7% per well (equivalent to 16.0 net wells).

· The Company hedged a total of 18,000 barrels of oil ("bbls") in Q1. These were hedged at a weighted average price of price US$68.68 per barrel of oil ("bbl").

In respect of the Company's newly formed acquisition vehicle Zephyr Hawk, as announced on 13 May 2025, the Company is pleased to report it is in the process of assessing approximately US$30 million of sourced drilling opportunities which have the potential to be funded through the Company's new US$100 million strategic partnership. The Company will provide further updates to investors as and when individual transactions are finalised.

Contacts

Qualified Person

Dr Gregor Maxwell, BSc Hons. Geology and Petroleum Geology, PhD, Technical Adviser to the Board of Zephyr Energy plc, who meets the criteria of a qualified person under the AIM Note for Mining and Oil & Gas Companies - June 2009, has reviewed and approved the technical information contained within this announcement.

Notes to Editors

Zephyr Energy plc (AIM: ZPHR) (OTCQB: ZPHRF) is a technology-led oil and gas company focused on responsible resource development from carbon-neutral operations in the Rocky Mountain region of the United States. The Company's mission is rooted in two core values: to be responsible stewards of its investors' capital, and to be responsible stewards of the environment in which it works.

Zephyr's flagship asset is an operated 46,000-acre leaseholding located in the Paradox Basin, Utah.

In addition to its operated assets, the Company owns working interests in a broad portfolio of non-operated producing wells across the Williston Basin in North Dakota and Montana. Cash flow from the Williston production will be used to fund the planned Paradox Basin development. In addition, the Board will consider further opportunistic value-accretive acquisitions.