Announcement • Jun 02
Helix Exploration Announces Noble Gas Isotope Results from Rudyard Helium Project Helix Exploration PLC announced the results of independent noble gas isotope analyses conducted across its three producing helium wells and production gas stream at Rudyard. Samples were analyzed by Dr. Peter Barry at Woods Hole Oceanographic Institution (WHOI) using a noble gas mass spectrometry in May 2026. Helium-3 to helium-4 ratios (3He/4He) are approximately 33 times above typical crustal helium values and carry approximately 1% helium in the raw well gas stream across all three producing wells. He isotopes consistently range from 0.665-0.690 relative to air (Ra) - indicating predominantly crustal gases (92%) and a whiff of mantle (8%). Consistency across all three wells (0.665-0.690 Ra) is a strong geological indicator that the Company is drawing from a single, uniform deep reservoir. Production gas stream records 855 parts per billion helium-3, following purification at Helix's Rudyard plant. Argon isotope signature (4°Ar/³6Ar: 7,950-9,665) is 27-33 times above atmospheric values and carries approximately 1,500 parts per million argon in the raw well gas stream. The profile is consistent with a potential underground argon source. Direct ³?Ar analysis is currently being arranged. Neon isotope ratios confirm crust and mantle noble gas components. Helium-3 Isotope Results: Sample ³He/4He Ratio (Ra) vs. Typical Crustal ³He concentration: Darwin-1 Well 0.665 Ra approximately 33 times above typical crustal 9.95 ppb ³He; Linda-1 Well approximately 0.675 Ra approximately 34 times above typical crustal 10.23 ppb ³He; Weil-1 Well approximately 0.685 Ra approximately 34 times above typical crustal 9.46 ppb ³He; Production Gas Stream 0.690 Ra approximately 35 times above typical crustal 855 ppb ³He. Ra = atmospheric ³He/4He reference (1.384 × 10?6). Typical crustal helium: approximately 0.02 Ra (range 0.01-0.05 Ra). Mantle reference: 8 Ra. Production gas concentrated to approximately 89.6% helium-4 at Helix's Rudyard plant; 855 ppb ³He reflects this concentration. The same analyses reveals a potentially significant argon finding. Argon that has been sealed deep underground for millions of years - shielded from cosmic radiation - becomes depleted in a naturally radioactive isotope called argon-39. This 'underground argon' is rare and is in high demand from the global physics community for use in ultra-sensitive dark matter detectors, where even trace radioactive contamination must be eliminated. There is currently only one known commercial source of underground argon in the world - a CO2 field in Cortez, Colorado - where the Global Argon Dark Matter Collaboration (GADMC), a consortium including Princeton University, ETH Zürich, and leading European physics laboratories, is extracting 120 tonnes for the DarkSide-20k dark matter experiment in Italy. There is no established commodity price; its value is defined by its unique scarcity. Helix's argon isotope results show that the argon in Rudyard's wells has the indications of gas that has been completely sealed underground for a long time, with no mixing with the atmosphere - the same geological characteristic that underpins known underground argon sources. High 40Ar/36Ar values (>8,000) are on par with those measured from Cortez (approximately 11,000), suggesting a similar deep source for the argon at Rudyard. These argon isotope ratios are 27 to 33 times above normal atmospheric values, and the wells carry approximately 1,500 parts per million argon in the raw gas stream. Furthermore, He/Ne values exceeding 60,000 confirm that Rudyard gas streams have experienced very little mixing with the modern atmosphere. These characteristics, together with the crust-mantle mixed helium and neon isotope signatures, paint a consistent picture of a deep, ancient, isolated reservoir. The Company has not yet carried out the specific test - a direct measurement of argon-39 - needed to confirm whether Rudyard's argon qualifies as underground argon. That measurement requires specialist equipment available at only a small number of laboratories worldwide, and Helix is actively making those arrangements. Until that test is completed, no equivalence to Cortez can be claimed. If the result is favorable, it would represent a discovery of considerable scientific and commercial significance and would position Rudyard as a potential second source of underground argon in the world. The concentration of argon-40 is approximately 3 times higher (approximately 1,500 ppm) at Rudyard versus reported concentrations at Cortez of approximately 600 ppm. The convergence of an exceptional ³He/4He signature, elevated mantle neon isotopes, and a highly radiogenic argon profile provides strong geochemical evidence that Rudyard draws from a deep, ancient, and isolated noble gas reservoir. These characteristics directly underpin the field's helium production and - pending 39Ar confirmation - may establish Rudyard as one of the most geochemically significant noble gas accumulations in North America. In accordance with the AIM Note for Mining and Oil and Gas Companies, Dr. Peter Barry, Associate Scientist with Tenure at WHOI, has reviewed the technical information contained herein. Dr. Barry has a PhD in geochemistry and approximately 20 years of experience working with noble gases. He has worked closely with the oil and gas industry for more than a decade. New Risk • Apr 29
New minor risk - Market cap size The company's market capitalization is less than US$100m. Market cap: UK£73.3m (US$98.8m) This is considered a minor risk. Companies with a small market capitalization are most likely businesses that have not yet released a product to market or are simply a very small company without a wide reach. Either way, risk is elevated with these companies because there is a chance the product may not come to fruition or the company's addressable market or demand may not be as large as expected. In addition, if the company's size is the main factor, it is less likely to have many investors and analysts following it and scrutinizing its performance and outlook. Currently, the following risks have been identified for the company: Major Risk Revenue is less than US$1m. Minor Risks Less than 3 years of financial data is available. Share price has been volatile over the past 3 months (11% average weekly change). Shareholders have been diluted in the past year (25% increase in shares outstanding). Market cap is less than US$100m (UK£73.3m market cap, or US$98.8m). Announcement • Apr 27
Helix Exploration PLC, Annual General Meeting, May 28, 2026 Helix Exploration PLC, Annual General Meeting, May 28, 2026. Location: eccleston yards, 25 eccleston place, sw1w 9nf, london United Kingdom 
