First Well in Malaysia Campaign Flows at 3,000 bopd

24 June 2026 - Singapore: Jadestone Energy plc (AIM:JSE) (the "Company" and together with its subsidiaries, "Jadestone" or the "Group"), an independent upstream production and development company focused on the Asia-Pacific region, is pleased to announce that the first well in the 2026 Malaysia infill drilling campaign on the PM323 PSC has been successfully drilled and brought online at ~3,000 bopd.

The 2026 Malaysia drilling campaign originally included two firm wells and a third contingent well targeting the southwest extension of the East Belumut field, which was identified in the 2023 infill programme. Based on the strong performance of the first well and the subsurface data gathered during drilling of the second well, the third well has now been confirmed and drilling has commenced. The Group's 2026 capital expenditure guidance[1] of US$50-80 million remains unchanged.

The first well in the 2026 campaign, EBA-18ST3, was drilled ~20% below budget. This is an excellent result considering the 1,200 metre horizontal reservoir section in the well at a total measured depth of 4,866 metres, the longest of any well drilled to date on the East Belumut field.

T. Mitch Little, Chief Executive Officer of Jadestone, commented:

"Our established operating capabilities in Malaysia, combined with our refreshed focus on operational excellence, have been further validated by the outcome of the EBA-18ST3 well. The result is an excellent start to this year's drilling campaign and will significantly increase our Malaysia production in the near-term against the backdrop of strengthened Brent oil prices, with our most recent Malaysia oil sales attracting a US$14/bbl premium to Brent. 

Following on from the significant progress on our Vietnam project earlier this year and the successful debt refinancing, this is further evidence of a business that is executing on its plan and strategy. We look forward to updating the market further on the second well in the campaign in the near-future."

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About Jadestone Energy

Jadestone Energy plc is an independent upstream company focused on the Asia-Pacific region. It has a balanced and increasingly diversified portfolio of production and development assets in Australia, Malaysia, Indonesia and Vietnam, all stable jurisdictions with a positive upstream investment climate.

The Company is pursuing a strategy to grow and diversify the Company's production base both organically, through developments such as Nam Du/U Minh in Vietnam and the Puteri Cluster offshore Malaysia, as well as through acquisitions that fit within Jadestone's financial framework and play to the Company's strengths in regional upstream development and operations and managing maturing oil assets. Jadestone delivers value in its acquisition strategy by enhancing returns through operating efficiencies, cost reductions and increased production through further investment.

Jadestone is a responsible operator and well positioned for the energy transition through its increasing gas production, by maximising recovery from existing brownfield developments and through its Net Zero pledge on Scope 1 & 2 GHG emissions from operated assets by 2040. This strategy is aligned with the IEA Net Zero by 2050 scenario, which stresses the necessity of continued investment in existing upstream assets to avoid an energy crisis and meet demand for oil and gas through the energy transition.

Jadestone Energy plc (LEI: 21380076GWJ8XDYKVQ37) is listed on the AIM market of the London Stock Exchange (AIM: JSE).  The Company is headquartered in Singapore.  For further information on the Company please visit www.jadestone-energy.com.

The announcement does not include inside information.