In Germany, Eavor Technologies used Well Radar™ ranging and interception services featuring passive magnetic ranging (PMR) in a first-of-its-kind advanced geothermal system (AGS) project, paving the way for geothermal power and district heating. This enabled the successful drilling of twin extended-reach wells 65 m apart—with challenging dogleg-severity requirements—that intercepted at final depth.

Eavor Technologies, a Calgary-based advanced-geothermal technology company, sought to install its Eavor-Loop™ technology at the Eavor Geretsried Project, south of Munich, Germany. This closed-loop geothermal system circulates a working fluid through a network of underground drilled passages to create a continuous heat exchanger that taps into the Earth’s natural heat.

The installation of these trailblazing AGS wells required two drilling rigs simultaneously drilling two extended-reach wells within 65 m [213 ft] with challenging dogleg-severity requirements and ending in an interception at final depth.

Eavor teamed with SLB to plan and execute a solution that offered the most precise well ranging and positioning as this complex project could not use conventional motor assemblies and wireline conveyance because sliding was not feasible in the carbonate reservoir formation.

Eavor used Well Radar services to drill the two wells at the same time. Identifying the relative position of the wells enabled executing the well program with safety and confidence. The use of RSS and active magnetic ranging technologies resulted in a more efficient execution with less emissions.

Directional and ranging data contributed significantly to the interpretation of the directional behavior of the two bottomhole assemblies deployed in tandem and overall improvement of the drilling process.

Precise well positioning was monitored with GyroLink™ definitive gyro-while-drilling service, which is unaffected by the interference field generated by the BHAs used to drill the wells. The GyroLink service has an advantage over magnetic surveys, especially when drilling in the east-west direction, enabling accurate wellbore positioning to reduce the uncertainty of the estimated distance and direction between the two twinned wells. Ranging showed at one point in the operations a large drift in azimuth in both wells. The GyroLink service resolved this uncertainty and enabled drilling to resume following recovery. Drilling of the two wells simultaneously from different rigs successfully achieved interception on the first attempt at 7,805 m [25,607 ft] MD.

A holistic approach and streamlined execution process helped deliver the complex project successfully. SLB monitored the operations on both rigs from a single Performance Live™ digital service delivery center. This project provided a significant milestone in demonstrating it is technically possible to drill configuration proposed in the Eavor‑Loop and setting a performance benchmark for future intercepts and geothermal applications in the energy industry.