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.

 21 May 2026

Zephyr Energy plc

("Zephyr" or the "Company")

Further divestment of undeveloped acreage

Zephyr Energy plc (AIM: ZPHR) (OTCQB: ZPHRF) is pleased to announce a further divestment of undeveloped non-core acreage in two separate transactions generating aggregate gross proceeds of US$2.275 million (subject to closing adjustments) (collectively, the "Divestment").

The 1,837 acres being divested are located in the Powder River Basin in Wyoming, U.S.  They were acquired by the Company as part of its US$7.3 million acquisition of a portfolio of both proved developed producing wells and largely undeveloped acreage, the completion of which was announced on 26 August 2025 (the "Acquisition"). The Divestment has an effective date of 1 June 2026, and both transactions are scheduled for completion (including the payment of consideration to Zephyr) in the week commencing 15 June 2026.

The Divestment follows previous disposals of non-core acreage that was also acquired as part of the Acquisition (as announced by the Company on 30 December 2025 and 24 March 2026).

By way of context, the US$7.3 million purchase price of the Acquisition was determined by the Company primarily based on the producing assets acquired. However, the transaction also included approximately 6,350 acres of largely undeveloped, potential development acreage in the Williston, Powder River, Denver-Julesburg and other Rocky Mountain basins. 

Since the completion of the Acquisition, and following the completion of the Divestment, the Acquisition will have:

·    Generated total asset sales of circa US$7.0 million (comprised of US$5.8 million in cash proceeds and the divestment of circa US$1.2 million in near-term plugging, abandonment and capital liabilities);

·    Generated US$1.7 million in revenue from acquired production (through to 31 December 2025);

The Company is currently evaluating options for the remaining undeveloped acreage acquired and will provide further updates in due course.

Colin Harrington, Chief Executive of Zephyr, said:

"I am delighted to report on the further generation of value from the undeveloped acreage acquired as part of the Acquisition. Since the completion of the US$7.3 million Acquisition in August last year, we have generated over US$8.7 million in revenues, cash from acreage disposals and from other cost savings. In doing so we have also retained the vast majority of production from the transaction, demonstrating the excellent economics of the deal."

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 in the Rocky Mountain region of the United States.

Its flagship operated asset is the 46,000-acre Paradox project in Utah, where an independent 2025 Competent Persons Report by Sproule International confirmed 2P reserves of 35.3 million barrels of oil equivalent ("boe") and total recoverable resources of 74.2 million boe.

Zephyr also holds a portfolio of non-operated production interests across the Williston and other Rocky Mountain basins, supported by a US$100 million strategic partnership designed to accelerate growth and enhance cash flow.