8 June 2026

Helix Exploration PLC

("Helix Exploration" or "Helix" or the "Company")

Agreement to Acquire Treasure State Drilling LLC and Drilling Rig

Helix Exploration PLC (AIM: HEX, OTCQB: HEXFF), the helium exploration and development company advancing the Rudyard Helium Project ("Rudyard") in northern Montana, is pleased to announce it has entered into a purchase and sale agreement to acquire 100 per cent of the membership interests of Treasure State Drilling LLC ("TSD") ("Acquisition"), a Montana-based drilling company, for total consideration of US$600,000, to be satisfied entirely by the issuance of new ordinary shares of 1 pence each ("Ordinary Shares") in Helix. The primary asset held by TSD is the drilling rig which has drilled all of Helix's existing Rudyard production wells. The Acquisition will give Helix complete control over rig access.

Highlights

•  Acquisition of 100 per cent. of TSD for US$600,000 paid wholly by the issuance of new ordinary shares in the Company meaning zero cash consideration being paid.

• Consideration paid represents a 37 per cent discount to the independent equipment appraisal of US$955,900 conducted by Enneberg Excavation LLC, a qualified engineering firm with over 22 years of Montana oilfield operations experience.

•  Removal of contract day rates on all future drilling at Rudyard - a direct and material reduction in per-well drilling costs with effect from completion.

•  Removal of mobilisation and demobilisation costs: TSD's rig is already positioned on site at Rudyard with no transport, rigging up, or rigging down costs required for the next well.

•  TSD's rig drilled all of Helix's existing Rudyard production wells and immediately deployable for further drilling.

•  Rig rated to 8,000 feet depth capable to drill Rudyard's Souris and Red River target formations and fully equipped for Helix's wider Montana exploration programme.

•  Key rig assets include an 800 HP Emsco mud pump, dual generator sets providing over 1,300 kW of power, and more than 22,000 feet of drill pipe inventory across multiple string sizes.

• The directors believe that, TSD's rig is the only drilling rig currently available in north-central Montana a region characterised by numerous oil and gas prospects and a growing operator base.

• Following Closing (as defined below), Helix intends to evaluate opportunities for TSD to undertake third-party contract drilling work when the rig is not required for Helix's own drilling programme. No third-party drilling contracts have been entered into and no revenue from third-party activity should be assumed at this stage.

Strategic Rationale

Owning a drilling rig represents a meaningful and permanent structural shift in Helix's cost base and operational control. In contract drilling, operators pay a day rate for rig usage regardless of whether the rig is actively drilling, on standby, or rigging up and down. These costs accumulate materially across a multi-well programme. By acquiring TSD outright, Helix removes this cost layer entirely with effect from Completion on future wells drilled at Rudyard and eliminating rig availability risk.

Equally significant is the elimination of mobilisation and demobilisation costs. Moving a drilling rig to a new location and subsequently moving it off involves substantial expenditure in logistics, transport, rigging, and associated downtime. TSD's rig is currently located at Rudyard, already positioned for the Company's next well. The acquisition ensures those costs are avoided entirely on all future Rudyard drilling activity.

Rig availability is a further strategic consideration. In active basins, drilling rigs are frequently committed to other operators, and companies must often wait months for a contracted rig to mobilise. Ownership eliminates this risk entirely. Following Completion, Helix can initiate drilling activity on its own timeline, respond to operational opportunities without constraint, and manage future drilling programmes as an integrated part of its production and development strategy.

A Standalone Commercial Opportunity

To the Board's knowledge, TSD's rig is the only drilling rig currently available in north-central Montana - a region that is home to numerous oil and gas operators and characterised by a diverse landscape of hydrocarbon prospects, including many smaller oil fields with the potential for exploration and development activity.

TSD will operate as a wholly owned but commercially independent subsidiary of Helix. In that capacity, TSD and its experienced crew are available for hire by area operators on a conventional contract drilling basis. The Board believes that the combination of TSD's rig being the only available unit in the region, an experienced crew with local knowledge, and a high oil price environment that may incentivise increased exploration and development activity across north-central Montana, creates a potential commercial opportunity for TSD as a standalone drilling business.

The Board emphasises that no third-party drilling contracts have been entered into, and no revenue from third-party activity should be assumed. However, the Board believes the conditions exist that could, over time, allow TSD's rig to generate contract revenue sufficient to be substantially self-funding. This potential - which is entirely additive to TSD's primary value to Helix as its captive drilling resource is not reflected in the consideration being paid for TSD.

The Rig

TSD's drilling rig is a Cardwell KB-150, rated to 8,000 feet depth -  suitable for Helix's Rudyard target formations in the Souris and Red River, which sit comfortably within that depth capability. TSD has been the sole drilling contractor for all activity at Rudyard to date, having drilled each of the Company's four production wells. The rig crew's familiarity with Rudyard's wellbore conditions, formation characteristics, and operational requirements represents a further practical and time-saving advantage.

The rig package includes dual generator sets providing more than 1,300 kW of on-site power generation, an 800 HP Emsco mud pump, two Bomco F-1000 mud pumps, and more than 22,000 feet of drill pipe inventory across multiple string sizes - providing full redundancy and flexibility for the Company's future drilling plans. The package also includes a Western Star semi winch truck, support vehicles, and a comprehensive complement of ancillary drilling equipment.

The aggregate appraised value of TSD's assets was independently assessed by Enneberg Excavation LLC  a qualified engineering firm with over 22 years of direct experience in Montana oilfield drilling operations  at US$955,900 on a conservative, low-end actual cash value basis. Helix is acquiring this full rig package for US$600,000.

Transaction Structure

The Acquisition will be effected through the purchase of 100 per cent. of the membership interests of TSD. Consideration of US$600,000 will be satisfied entirely by the issuance of new Ordinary Shares in Helix Exploration PLC at a price determined by reference to a 20 day VWAP of Helix shares from date of signing of the purchase and sale agreement to the shareholders of TSD ("Sellers"). Completion of the Acquisition is subject to the satisfaction or waiver of certain standard conditions. The Sellers have also undertaken to settle existing liabilities owed by TSD.

Bo Sears, Chief Executive Officer of Helix Exploration PLC, commented: "Owning our rig is a game-changer for Helix. Every well we drill from this point forward will be drilled without a day rate invoice and without a mobilisation bill. Those are real costs that every E&P operator in our position absorbs on every well - and we have just eliminated them. Permanently.

"The economics of this transaction are straightforward. We are paying US$600,000 - entirely in shares - for an asset package that an independent qualified appraiser has assessed at close to US$1 million. And in return, we eliminate what would otherwise be a meaningful recurring cost on every future well we drill. We believe this is an excellent outcome for Helix shareholders.

"The strategic value goes beyond Helix's potential future drilling programmes. To my knowledge, this is the only drilling rig currently available in north-central Montana. That matters. The area is rich in oil and gas prospects, and with oil prices where they are today, we believe there is the potential for increased exploration and development activity across the region. TSD and its crew are available for hire. We have not yet entered into any third-party contracts yet - but the commercial opportunity is real, and we believe it has the potential to make this rig substantially self-funding. We potentially getting our captive drilling capability at no net cost to the business in the medium term, and potentially at no cost at all.

"This rig has already drilled all four of our Rudyard wells. It knows our field, it knows our crew, and it is sitting on site right now. We are ready to go."

This announcement contains inside information for the purposes of the UK Market Abuse Regulation, and the Directors of the Company are responsible for the release of this announcement.

Enquiries

Helix Exploration PLC

Cairn - Nominated Adviser

Hannam & Partners - Broker

Notes to Editors

Helix Exploration is a helium exploration company focused on the exploration and development of helium deposits within the 'Montana Helium Fairway'. Founded by industry experts with extensive experience of helium systems in the US, the Company listed in April 2024.

Helix is focused on production at its Rudyard Project in northern Montana, taking advantage of existing infrastructure and low-cost processing to target first gas in 2025. The Company has four production wells targeting up to 236ft Helium / Nitrogen gas in the Souris and Red River formations, flowing up to 3,800 Mcf/day at 1.2% helium. Rudyard field can support multiple production wells and has potential to generate net revenue of $115-$220 million over a 12.5-year life of field.

Helix is committed to open and transparent communication with investors and the wider market as the project progresses through development into production.

"Our approach is simple: build scale efficiently, develop resources strategically, and deliver near-term cash flow."

Bo Sears, Chief Executive Officer

The Company's Admission Document, and other information required pursuant to AIM Rule 26, is available on the Company's website at https://www.helixexploration.com/.

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.