Horizon Energy is very encouraged by the NSTA recently announced results of the Pensacola appraisal well 41/05a-3 drilled by Shell earlier this year targeting the Haupt Dolomite. The Haupt Dolomite is the same reservoir target as Horizon Energy’s Dabinett prospect. In the Pensacola well, the Haupt Dolomite gross reservoir thickness was 59.74 metres and on test the well flowed a maximum 38.2 mmscfd on a 64” choke. The cumulative gas production was 64 mmscf with condensate production of 151 stb. This was an excellent result for the well which targeted the crest of an isolated Haupt carbonate platform. The original Pensacola discovery, drilled by Shell in 2022, tested both oil and gas in a carbonate slope position, a sub-optimal position for encountering a thick good quality reservoir. The Crosgan gas discovery appraisal well drilled by ONE-Dyas in 2023 on a separate isolated carbonate platform to Pensacola encountered a 140-metre gross thickness Haupt Dolomite reservoir and was tested with a maximum flow of 26.5 mmscfd.

The appraisal well results further confirm that the main Haupt Dolomite carbonate platform under the Mid North Sea High, the target for the Dabinett prospect in Block 42/05, could have a reservoir thickness significantly greater than 60 metres. In the adjacent block to the Dabinett prospect, the Ossian discovery well 42/04-1 drilled by ONE-Dyas in 2019 encountered a 65 metre Haupt Dolomite reservoir at a location internal to the platform margin. The Dabinett prospect will target a platform margin location and is expected to encounter the highest quality and enhanced reservoir properties and productivity, as evidenced in analogue oil and gas fields in Poland. The Dabinett prospect would be the first well to target this highly prospective area of the Haupt carbonate platform on the Mid North Sea High of the Southern North Sea.

The Dabinett prospect has significant mean prospective resources of 663 Bscf and 16 mmstb condensate as independently assessed by ERC Equipoise. A discovery of this volume would provide a significant gas resource from the UK North Sea and internal company estimates suggest the tax revenue for the UK could potentially exceed £1.75 billion. UK gas production has a better environmental footprint as compared to LNG and other imports and provides enhanced energy security.

Horizon Energy applied to the NSTA for a two-year extension of Licence P2557 containing the Dabinett prospect. On the 1 st September 2025, the NSTA approved the request and Phase C of the Licence now expires 30 th November 2028. The additional timeframe allows the Dabinett prospect to be progressed under hopefully more supportive government policies. Horizon Energy is looking to enlist an industry partner or partners to participate in this exciting prospect which is increasingly being derisked by the recent exploration discoveries and appraisal successes targeting the Haupt Dolomite, both in the UK and in Poland.