First Deployment of ÍSOR’s Flexible Couplings in a Geothermal Production Well

Reykjavík, Iceland – A major milestone has been reached in geothermal well technology as ÍSOR (Iceland GeoSurvey) successfully deployed Flexible Couplings Technology in a live geothermal production well for the first time. The couplings were installed in well NJ-37 at Nesjavellir Power Plant, a key step in advancing thermal stress mitigation strategies for superhot geothermal drilling.

What are Flexible Couplings?

Designed to address the challenges of thermal expansion, flexible couplings allow controlled movement of casing sections, reducing the risk of material failure in high-temperature geothermal wells. Without such solutions, steel casing deforms under extreme heat, threatening well integrity.

From Lab to Field Deployment

Developed over a decade of research, the couplings were tested in previous EU-funded projects (GeoWell, DEEPEGS, GeConnect) before being integrated into the COMPASS Project, which focuses on deep drilling advancements for ultra-high-temperature geothermal wells.

• In this latest test:
  67 couplings were installed in NJ-37’s production casing.
• Validated in 250-300°C conditions, preparing for 450-550°C applications.
• Key step toward IDDP-3 and future deep drilling initiatives

Why This Matters for Superhot Geothermal

Superhot geothermal wells promise unprecedented energy output, but thermal stress management remains a key challenge. By ensuring well integrity at extreme temperatures, flexible couplings could significantly improve the reliability and lifespan of deep geothermal wells.

What’s Next?

The performance of the installed couplings will be monitored and analyzed, paving the way for broader adoption in superhot and deep geothermal projects worldwide.

This deployment represents a key achievement for the COMPASS Project, bringing geothermal well engineering one step closer to enabling the next generation of sustainable energy production.

Borholur – Skriðtengi (Youtube Video)

Full press release from ÍSOR: Skriðtengin komin í holu! – isor.is