Periodic Reporting for period 1 - HOCLOOP (A circular by design environmentally friendly geothermal energy solution based on a horizontal closed loop - HOCLOOP)
Periodo di rendicontazione: 2022-10-01 al 2023-11-30
Geothermal energy is a clean renewable and underexploited energy source that enables constant power output and holds a huge potential to mitigate emissions of greenhouse gases from the energy production sector. Conventional geothermal exploitation is based on heat extraction from scarce hot aquifers which circulate within permeable rocks. This severely limits the use of this energy and implies high cost and risks for the development of exploitation projects.
HOCLOOP aims to mitigate the drawbacks of conventional geothermal exploitation by using an innovative horizontal closed loop solution for the extraction of heat from deep or shallow formation rocks. The solution is based on new drilling technology and solves the challenges of conventional construction of geothermal wells. HOCLOOP’s concept aims to improve the power production due to extended reach horizontal drilling with a large hole size. Further improvement is expected to be achieved by use of alternative circulation fluids to water, such as CO2 based fluids. It is expected that the solution can reduce the LCOE compared to the conventional solution and meet the SET plan targets. The project will develop the tools to enable the proposed geothermal solution and demonstrate the technology in a full-scale test operation to TRL5.
The work within HOCLOOP will cover the development and validation of models for the heat flow and investigate the possibility for improving the electricity production by using alternative fluids to water. The work will also cover the investigation of potential EU pilot sites, environmental assessment, and the social acceptance. It is expected that the HOCLOOP concept will enable exploitation of geothermal energy sources in new regions with- or without good hydrothermal reservoirs. The solution is foreseen to be integrated with other renewables to improve the reliability of the power supply and grid stability, and to be applicable to a variety of geological conditions. HOCLOOP is also expected to solve the main issues of geothermal energy related to emissions, seismicity, and environmental aspects. 9 partners from 6 European countries with complementary expertise join forces for this 42-month project.
HOCLOOP aims to mitigate the drawbacks of conventional geothermal exploitation by using an innovative horizontal closed loop solution for the extraction of heat from deep or shallow formation rocks. The solution is based on new drilling technology and solves the challenges of conventional construction of geothermal wells. HOCLOOP’s concept aims to improve the power production due to extended reach horizontal drilling with a large hole size. Further improvement is expected to be achieved by use of alternative circulation fluids to water, such as CO2 based fluids. It is expected that the solution can reduce the LCOE compared to the conventional solution and meet the SET plan targets. The project will develop the tools to enable the proposed geothermal solution and demonstrate the technology in a full-scale test operation to TRL5.
The work within HOCLOOP will cover the development and validation of models for the heat flow and investigate the possibility for improving the electricity production by using alternative fluids to water. The work will also cover the investigation of potential EU pilot sites, environmental assessment, and the social acceptance. It is expected that the HOCLOOP concept will enable exploitation of geothermal energy sources in new regions with- or without good hydrothermal reservoirs. The solution is foreseen to be integrated with other renewables to improve the reliability of the power supply and grid stability, and to be applicable to a variety of geological conditions. HOCLOOP is also expected to solve the main issues of geothermal energy related to emissions, seismicity, and environmental aspects. 9 partners from 6 European countries with complementary expertise join forces for this 42-month project.
Several important achievements beyond the SoA have been reached and much more is being built on the developments so far:
• Numerical tools to simulate the HOCLOOP heat extraction concept and describe the evolution of temperature in the surrounding rock and heat transport towards the well have been developed. These tools handle a wide range of geological characteristics and their impact in long-term heat production.
• The effects of local groundwater in the heat production are quantifiable and predictable overtime.
• Mass flow rate, the depth of the well and the geothermal gradient have the strongest impact in the hear extraction, in comparison to geometrical characteristics, operational conditions and geological settings. The presence of any fluid (mud, water, oil-based) in the annulus part of the well completion slightly deteriorates the performance of the process, in terms of outlet temperature and power production.
• The effect of eccentricity on the thermo-hydraulic performance of the pipe-in-pipe arrangement of the HOCLOOP concept is that the Nusselt number decreases drastically with increase in eccentricity and the friction factor decreases with increase in eccentricity. The first, has a negative effect on system’s performance by minimizing the power production, whereas the second finding has a positive effect by decreasing the power demands for circulating the fluid.
• The geological characterization of four different European potential pilot sites is completed (D4.1) and reveals some limitations about geological or surface integration data availability. Subsequent literature studies may prove useful in overcoming the limitations.
• The design and material selection for the DHS is completed and the testing of its components initiated. Optimization of the design and materials is ongoing based on the results of the tests. Special focus is on the critical components for the DHS, i.e. Centralizer, Tension Anchor, Bottom Hole Sub, Tubing Hanger and the DHS Handling Protector.
• Preliminary data shows that the social acceptance towards geothermal energy exploitation is generally positive, if seismicity risks, emissions of toxic gases, and general local environmental impacts are clearly presented and handled. The HOCLOOP concept is expected to improve the acceptance even further.
• Numerical tools to simulate the HOCLOOP heat extraction concept and describe the evolution of temperature in the surrounding rock and heat transport towards the well have been developed. These tools handle a wide range of geological characteristics and their impact in long-term heat production.
• The effects of local groundwater in the heat production are quantifiable and predictable overtime.
• Mass flow rate, the depth of the well and the geothermal gradient have the strongest impact in the hear extraction, in comparison to geometrical characteristics, operational conditions and geological settings. The presence of any fluid (mud, water, oil-based) in the annulus part of the well completion slightly deteriorates the performance of the process, in terms of outlet temperature and power production.
• The effect of eccentricity on the thermo-hydraulic performance of the pipe-in-pipe arrangement of the HOCLOOP concept is that the Nusselt number decreases drastically with increase in eccentricity and the friction factor decreases with increase in eccentricity. The first, has a negative effect on system’s performance by minimizing the power production, whereas the second finding has a positive effect by decreasing the power demands for circulating the fluid.
• The geological characterization of four different European potential pilot sites is completed (D4.1) and reveals some limitations about geological or surface integration data availability. Subsequent literature studies may prove useful in overcoming the limitations.
• The design and material selection for the DHS is completed and the testing of its components initiated. Optimization of the design and materials is ongoing based on the results of the tests. Special focus is on the critical components for the DHS, i.e. Centralizer, Tension Anchor, Bottom Hole Sub, Tubing Hanger and the DHS Handling Protector.
• Preliminary data shows that the social acceptance towards geothermal energy exploitation is generally positive, if seismicity risks, emissions of toxic gases, and general local environmental impacts are clearly presented and handled. The HOCLOOP concept is expected to improve the acceptance even further.
The project is bringing a radically new technology for the exploitation of geothermal resources in larger geological settings, securing minimal environmental impact and getting social acceptance. The progress is following the plan and we expect getting more results to evaluate its viability (financial, technical and social) by the end of 2024.
Commercialization and acceleration is of paramount importance for HOCLOOP and has been specifically addressed in the project. The company REELWELL, partner of the project and owner of the technology has large ambitions to further promote this solution. REELWELL has decided to open a dedicated company (Geotherma AS) to exploit the close loop technology and the technical outcomes gathered along this EU funded project. We consider this as a very important milestone of the project that hits the expectations of the EU when providing funding to initiatives such as a HOCLOOP. REELWELL has also created two new positions in the company and two young high skilled employees have been hired in 2023.
Commercialization and acceleration is of paramount importance for HOCLOOP and has been specifically addressed in the project. The company REELWELL, partner of the project and owner of the technology has large ambitions to further promote this solution. REELWELL has decided to open a dedicated company (Geotherma AS) to exploit the close loop technology and the technical outcomes gathered along this EU funded project. We consider this as a very important milestone of the project that hits the expectations of the EU when providing funding to initiatives such as a HOCLOOP. REELWELL has also created two new positions in the company and two young high skilled employees have been hired in 2023.