Lachowice 7 Well - Completion of the Acid Stimulation Treatment and Commencement of Production Testing

Calgary, Alberta – September 25, 2026 – Horizon PetroleumLtd. ("Horizon" or the "Company") (TSX-V: HPL; FRA: HPM;Tradegate: HPM) is pleased to announce that, further to its press releasedated September 14, 2026, its wholly owned Polish subsidiary, Energia KarpatyZachodnie sp. z o.o. ("EKZ"), has completed the acid stimulation treatment at the Lachowice 7 ("L7") well in southern Poland and has commenced production testing operations.

Following completion of the acid stimulation, a coiledtubing unit was installed on the well and nitrogen was circulated into theproduction tubing to unload the well and initiate flow. At approximately 06:30CET today, the L7 well began flowing gas and condensate naturally, withoutfurther assistance from the coiled tubing or nitrogen and continues to flow.

Preliminary flowback rates have reached 5.5 million cubicfeet per day (“MMcf/d”) of natural gas at a flowing wellhead pressure ofapproximately 2,500 pounds per square inch (or “PSI”) through a choke size of28/64 inch. The Company considers these initial results encouraging; however,the well remains in the cleanup phase and the reported rates are preliminaryand subject to change as the well stabilizes.

During the mechanical portion of the workover program, asignificant volume of water was lost into the formation. This water, togetherwith the acid used during the stimulation treatment, is now being recoveredthrough the surface production testing equipment along with the producednatural gas and condensate. The recovery of these fluids is a normal part ofthe well cleanup process following a workover and stimulation treatment.

The Company expects to continue flowing the well atvariable rates for approximately 24 to 36 hours during the cleanup period, oruntil gas and liquid rates and flowing pressures have sufficiently stabilized.The well will then be shut in for a short period to allow pressure to build,followed by a production logging operation to identify inflow points within thereservoir. The well will subsequently undergo the main flow and pressurebuild-up portion of the testing program.

The L7 well has previously demonstrated significant gasdeliverability, having been tested by previous operators at rates of up to 8.9MMcf/d (in 1994), including a sustained two-week flow period at approximately3.0 MMcf/d (in 1999), based on well reports in the Company’s possession. Thecurrent testing program is designed to provide Horizon with additionalinformation regarding reservoir performance, inflow distribution, pressurebehaviour and sustainable production potential following the workover and acidstimulation.

The commencement of flow testing has also generatedsignificant interest in the local community, with the well flare visible fromsurrounding towns and the start of testing receiving coverage in local media.

While the Company is encouraged by the initial flowbackresults, the rates observed during the cleanup period should be consideredpreliminary and should not be interpreted as representative of stabilized orlong-term production rates. Final conclusions regarding the well'sdeliverability will be made following completion of the planned flow andpressure build-up testing program.

The Company will provide further updates as production testingoperations progress.

The original Press Release PDF document is available here.

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