Tullow publishes reserves report

26 September 2025 Ð Tullow Oil plc (Tullow) has published its mid-year 2025 reserves report. Reserves estimates for Ghana have been extracted from a reserves report (dated 26 September 2025) prepared by the appointed external auditor, TRACS International Limited, based on data available to the end of June 2025. Reserves estimates for C™te d'Ivoire are based on the Reserves Report prepared by TRACS as of 31 December 2024, adjusted for 1H 2025 production.

Total reserves of 113.8 mmboe as of 30 June 2025 compare with total reserves of 128.5 mmboe as of 31 December 2024, both excluding Gabon. The reduction reflects 7.4 mmboe of production and revisions associated with production performance during 1H 2025 of 7.3 mmboe (Jubilee 6.3 mmboe and TEN 1.0 mmboe).

Following the Memorandum of Understanding with the Government of Ghana to extend the production licences to 2040, TRACS has estimated that 14.7 mmboe of Jubilee Contingent Resources and 3.5 mmboe of TEN Contingent Resources would move to 2P Reserves once the extensions are executed.

With the new 4D seismic data acquired in 1Q 2025 and an Ocean Bottom Node (OBN) survey planned for 4Q 2025, Tullow expects to mature new projects and increase 2P reserves in Ghana. This is further supported by ongoing work with the Government of Ghana in relation to a Plan of Further Development for Jubilee, which covers the licence extensions and further drilling opportunities.

The report is available on the website here: https://www.tullowoil.com/investors/results-reports-and-presentations/

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