Operational Update

3 November 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, provides the following operational update.

Following the resumption of production at CWLH, Group production has risen to ~19,000 boepd, with the Stag field remaining offline (see below). 2026 Group production guidance of 16-18,000 boepd is unchanged.

CWLH

As previously disclosed, one of the CWLH fields’ subsea riser J-tube’s required repairs prior to a safe return to operations following the Okha FPSO’s scheduled dry-dock earlier in 2026. The repairs were successful, and the Okha FPSO reconnected to the field’s subsea infrastructure.

A return to production operations and well testing commenced in late September. All but one of the production wells have been returned to production, with the field producing ~8,000 bopd gross (~2,700 bopd net) in recent days. An assessment of the final production well has identified an issue that requires remediation. The operator is evaluating options to safely restore production from this well at the earliest possible opportunity. Further updates will be provided in due course.

Vietnam

Jadestone is in the final stages of discussions with a select list of counterparties for the Nam Du/U Minh project farm-out. In parallel, the key development contracts for the project are also nearing completion.

The project continues to benefit from the strong support of Vietnam government stakeholders. In late October 2026, the parties to the ND/UM Gas Sales and Purchase Agreement (“GSPA”) extended the GSPA conditions precedent period to allow for finalisation of contract awards.

The Company continues to target a final investment decision before the end of 2026.

Montara

Since a return to stable operations following the successful re-injection compressor upgrade earlier in 2026, Montara has been Jadestone’s highest reliability asset, averaging ~97% uptime.

A ~300kbbls cargo of Montara crude was lifted in early October, with a realised price of ~US$133/bbl (average Dated Brent for the month of October 2026 plus a premium of ~US$8/bbl).

Jadestone is making good progress on addressing the remaining requirements of NOPSEMA’s General Direction #2043 and Prohibition Notice #1875 by early 2027.

Akatara

Akatara continues to perform in line with expectations, with 2026 production still expected to be broadly in line with 2025 levels. Since returning to production following a short maintenance related shut-down during April 2026, Akatara uptime has averaged ~96%.

Stag

The Company continues to expect deployment of a replacement CALM buoy to the Stag field in Q1 2027 ahead of a resumption of production during Q2 2027. As previously disclosed, Stag business interruption insurance runs to May 2027, with separate insurance cover of ~US$30 million expected to cover the costs of retrieving the existing CALM buoy and acquiring and installing its replacement.

Peninsular Malaysia (“PenMal”)

Year-to-date PenMal production is ahead of expectations, driven by the positive results of the successful Phase 9 drilling program on the PM323 field earlier in 2026 and continued high reliability with unplanned downtime of ~4% year to date.

Negotiations continue with the Malaysian upstream regulator over an extension to the PM323 PSC on improved terms, with the Company remaining confident that the extension will be secured in the near-term.

Recent premiums for PenMal crude liftings have been in the ~US$4-7/bbl range.

Hedging

The Company currently has ~0.8 million barrels hedged over the six months ending March 2027 at a weighted average price of US$81.45/bbl (excluding asset specific premiums), representing ~47% of forecast oil and condensate liftings during the period. These figures include recent hedges of 100,000 barrels by way of zero cost collars with floors of US$80-90/bbl and caps of US$100-112/bbl.