THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF THE MARKET ABUSE REGULATION (EU) 596/2014 (WHICH FORMS PART OF DOMESTIC UK LAW PURSUANT TO THE EUROPEAN UNION (WITHDRAWAL) ACT 2018) ("UK MAR").

THIS ANNOUNCEMENT AND THE INFORMATION CONTAINED HEREIN IS RESTRICTED AND IS NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, DIRECTLY OR INDIRECTLY, IN WHOLE OR IN PART, IN OR INTO, THE UNITED STATES OF AMERICA, AUSTRALIA, NEW ZEALAND, CANADA, JAPAN OR THE REPUBLIC OF SOUTH AFRICA OR ANY OTHER JURISDICTION WHERE, OR TO ANY OTHER PERSON TO WHOM, TO DO SO MIGHT CONSTITUTE A VIOLATION OR BREACH OF ANY APPLICABLE LAW OR REGULATION.

16 September 2026

Helix Exploration PLC

("Helix" or the "Company")

Rudyard - Ollie #1 Well Spud

Helix Exploration PLC (AIM: HEX, OTCQB: HEXFF), the US-focused helium production and liquefaction company, is pleased to announce that the Ollie #1 well was spudded on 14 September 2026.

Helix has three production wells at Rudyard - Darwin #1, Linda #1 and Weil #1 - all of which have produced high grade, commercial helium and are connected to the gathering system, providing throughput to the PSA plant.

Ollie #1 is intended to be the fourth production well in the Northern Dome of the Rudyard field and is targeting the same proven Souris River and Red River formations that the current well stock have produced from. The northernmost well in the Northern Dome, the well is situated approximately one mile north of Weil #1.

The Ollie #1 well has an estimated total depth of approximately 5,500 ft and is expected to take approximately 21 days to drill, followed by wireline logging, extended flow testing and gas analysis.

Subject to flow testing and gas analysis, Helix intends to tie the well into the existing gathering system at Weil #1 and connect it to the PSA Plant, within the existing current membrane capacity.

A further announcement will be made upon completion of the Ollie #1 well.

The Company is currently surveying several additional helium well locations as candidates for the next well following completion of Ollie #1, as part of its planned production expansion programme.

Bo Sears, Chief Executive Officer, commented:

"We're delighted to be drilling Ollie #1 - intended as the fourth production well at Rudyard, joining Darwin, Linda and Weil. This represents the next stage of the Company's drilling campaign at the Rudyard field to increase production. This will be carried out in parallel with the planned purchase and installation of a new membrane, which the Company expects to increase the available throughput capacity of the facility and, subject to production volumes and sales arrangements, support increased sales volumes in due course.

We appreciate the timely permitting of the Ollie #1 well by the Montana Board of Oil and Gas Conservation. Having acquired our own drilling rig this summer, Helix now has full operational control over its field expansion programme, and we are surveying options to be the next well in the programme following completion of Ollie #1."

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Notes to Editors

Helix Exploration PLC is a US based helium production and liquefaction company listed on the London Stock Exchange (LSE: HEX), with operations spanning the helium value chain from production through to liquefaction. Its flagship Rudyard Project in Montana is the state's first producing helium field, with three stacked helium-bearing reservoirs in a proven geological setting and an initial three wells delivering commercial helium flow rates. Production commenced in February 2026 through an on-site PSA processing facility, with first commercial sales commencing in July 2026 to an industrial gases group. Production is currently subject to a regulatory pause requested by the MBOGC, as announced on 3 September 2026.

Following the acquisition of the Keyes Helium Complex in Oklahoma, one of only six operational helium liquefaction facilities in the United States, Helix has become an independent US helium producer owning both upstream production and liquefaction infrastructure. The acquisition positions the Company to capture greater value across the supply chain, process both its own and third-party helium, and support the growing North American helium market with flexible, independent liquefaction capacity.

Helix's assets are characterised by low-cost production, established infrastructure, significant and fully funded expansion potential, and a strategy focused on building a fully integrated helium business capable of delivering sustainable long-term growth.

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Caution regarding forward looking statements

Certain statements in this announcement, are, or may be deemed to be, forward looking statements. Forward looking statements are identified by their use of terms and phrases such as ''believe'', ''could'', "should" ''envisage'', ''estimate'', ''intend'', ''may'', ''plan'', ''potentially'', "expect", ''will'' or the negative of those, variations or comparable expressions, including references to assumptions. These forward-looking statements are not based on historical facts but rather on the Directors' current expectations and assumptions regarding the Company's future growth, results of operations, performance, future capital and other expenditures (including the amount, nature and sources of funding thereof), competitive advantages, business prospects and opportunities. Such forward looking statements reflect the Directors' current beliefs and assumptions and are based on information currently available to the Directors.