Horizon Petroleum confirmed this week that the Lachowice 7 well in southern Poland passed two casing pressure tests, verifying wellbore integrity ahead of a planned workover program. The milestone, announced following the company’s July 23, 2026 press release, clears a key technical hurdle for its Polish subsidiary, Energia Karpaty Zachodnie (EKZ), which has already begun re-entry operations at the site.
Re-entry operations underway at Lachowice 7
Rig mobilization and installation are complete, and EKZ has formally kicked off re-entry operations at Lachowice 7. Early progress has been fast. The team has already drilled out cement and mechanical suspension plugs and run a milling assembly to 8,878 feet—solid ground covered in the opening phase.
The two casing pressure tests were the critical early milestone, and both came back clean. That result wasn’t guaranteed. Re-entering a previously suspended well always carries the risk that casing has degraded, and passing both tests removes that uncertainty, giving the team a stable foundation to build on.
It’s what lets the team safely reach and stimulate that reservoir section without risking uncontrolled fluid movement or equipment failure downhole.
With those checks done, Horizon says the workover program can move forward. Operations are on track.
Why wellbore integrity confirmation matters for the program
Not every step in a workover carries equal weight. Casing integrity was flagged upfront as one of the key risks in re-entering Lachowice 7—if the wellbore had failed either pressure test, the path forward would’ve looked very different, and considerably more complicated.
COO Roger McMechan put it plainly in the company’s update: “Confirming the integrity of the well casing mitigates one of the key risks in re-entering the well.” That kind of direct acknowledgment signals how closely the team was watching this result.
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The well targets a naturally fractured Upper Devonian carbonate reservoir with a gross interval of 213 feet—a meaningful target zone, but one requiring careful, staged access. Wellbore integrity isn’t a procedural box to check here. It’s what lets the team safely reach and stimulate that reservoir section without risking uncontrolled fluid movement or equipment failure downhole. With integrity confirmed, the program can proceed as designed.
Next steps: Perforation, acid stimulation, and production testing
The next phase focuses on removing existing downhole packer and completion equipment. Once cleared, the team will apply new perforations to the Upper Devonian carbonate reservoir—the naturally fractured zone at the heart of the Lachowice gas accumulation.
After perforation comes stimulation. The plan calls for a diverted acid stimulation, a technique designed to improve flow through fractured carbonate by chemically treating the reservoir, opening up pathways and encouraging more consistent, sustainable gas movement toward the wellbore. Then comes a production test—not about theoretical potential, but confirming real-world flow performance. It’ll tell the team whether the reservoir can deliver at rates that support long-term commercial production.
Horizon Petroleum says stimulation and production testing are expected to begin near the end of August and run into early September 2026. Based on current progress, the company says the program is on track to meet that window. Once Phase 1 wraps up, the well will be suspended for production—the final step in this initial development plan.
Background: Lachowice as a potential domestic gas source for Poland
Lachowice 7 doesn’t exist in isolation. It sits within a broader context—for Horizon’s development strategy and for Poland’s energy picture more widely.
Horizon operates in Poland entirely through EKZ, its wholly owned subsidiary Energia Karpaty Zachodnie sp. z o.o. The Lachowice workover is Phase 1 of the company’s development plan for the accumulation. If production testing confirms sustainable flow, it sets the stage for what comes next.
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Poland’s appetite for domestic gas has grown considerably in recent years. Like much of Europe, the country has been working to diversify its energy sources and cut dependence on imported supply. A new domestic natural gas source in a proven geological setting fits directly into that push. Horizon has described the Lachowice gas accumulation as having the potential to become a significant new domestic source of natural gas for Poland—a measured claim that still depends on what the production test shows. But the early signs from this workover point in the right direction.
Two casing tests confirming integrity
Here’s where things stand. EKZ has completed rig installation and begun re-entry operations at Lachowice 7, with two casing pressure tests confirming wellbore integrity and clearing one of the program’s most significant early risks. The team has drilled to 8,878 feet and is progressing through the workover sequence.
Next up: removal of existing downhole equipment, new perforations into the Upper Devonian carbonate reservoir, diverted acid stimulation, and a production test to evaluate sustainable flow. That testing phase is expected to run from late August into early September 2026. The results will determine whether Lachowice 7 moves toward long-term production—and whether the accumulation can deliver on its potential as a meaningful domestic gas source for Poland.
Staff Writer
Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.
