EAPOSYS selects Halliburton to accelerate deployment of closed-loop geothermal solution

The Advanced Geothermal Systems (AGS) technology of EAPOSYS (source: EAPOSYS)

Carlo Cariaga 10 Oct 2025

EAPOSYS has signed an agreement with Halliburton (NYSE: HAL) to conduct a subsurface feasibility study to help accelerate the deployment of EAPOSYS Advanced Geothermal Systems (AGS). This study will contribute to the industrialization of EAPOSYS engineering and well design, followed by site-related geothermal and stratigraphic considerations to minimize drilling risk, and advance the EAPOSYS scalable well design. 

“EAPOSYS SA, a start-up based in Biel/Bienne, has developed an innovative, patented, closed-loop architecture to deploy AGS anywhere in the world,” said Naomi Vouillamoz, CEO and co-founder of EAPOSYS. “AGS offers essential qualities for an affordable and sustainable energy future with unique advantages.” 

Delivering increased predictability and efficiency through AGS

EAPOSYS seeks to advance a closed-loop geothermal installation that circulates a working fluid through sealed boreholes to recover the heat from deep hot rock layers. It will be purely conductive system using a radiator-like architecture between an injection and production well.

The company states the following advantages for the proposed system:

• Predictability: EAPOSYS can control energy output with high accuracy and utilizes assets and technologies from the oil and gas industry.
• Durability: EAPOSYS architecture allows for energy generation over a long period of time.
• Efficiency: Each installation is customized to meet local requirements, operates without power loss for pumping thanks to the thermosiphon effect, and requires minimal land footprint.
• Environmental Impact: Closed loops reduce water needs and treatments without fluid exchange or stimulation.

The initial applications for EAPOSYS AGS will be district heating for communities and municipalities, industrial heat for sectors such as greenhouses, food and beverage, and manufacturing. It will also support cascade applications that co-generate electricity and heat using Organic Rankine Cycle systems.

The patented service well

The unique feature of the EAPOSYS AGS lies in the patented service well that allows for the incremental, butterfly-shaped deployment of the installation across the targeted heat depth sections. It also reduces drilling risk by reducing the length of the laterals, and provides access to individual loops for maintenance.

Once the injection and production wells have been completed, the horizontal well sections are drilled from the service well (dashed black) and connected to the injection/production wells to create EAPOLAPs heat recovery conduits in a circular closed loop. The “butterfly-shaped” geometry offers further deployment flexibility in various geological settings.

EAPOSYS deploys its solutions through national or regional consortia: EAPOLABs. Since the launch of the EAPOLAB initiative in 2023, EAPOSYS engaged in active discussions with industry partners, energy companies, and public authorities in several geographies for upcoming operations. The first EAPOLAB platform, SwissDGS, was established in Zurich, Switzerland, at the end of 2024, with two leading Swiss engineering firms: Basler & Hofmann and Amberg Group. 

“Energy is at the core of every human society: guarantee of supply, sustainability, affordability, and energy as a common good is an essential ethical attribute which EAPOSYS AGS strives to contribute to,” said Vouillamoz.

Source: Email correspondence