Advancing the Future of Geothermal Energy: Vallourec’s Approach to Applications Up to 500°C
Geothermal energy is a key pillar of the energy transition, offering clean and sustainable power generation. High-temperature geothermal projects are particularly promising as they can deliver substantially greater energy output per well, contributing to the reduction of the Levelized Cost of Energy (LCOE). However, operating in these extreme environments presents significant challenges, requiring materials and technologies to be rigorously validated for such conditions to ensure long term well integrity. Vallourec is proud to lead advancements in this field, pushing the boundaries of what is possible for geothermal well operations.
On December 3rd, Vallourec presented its technical paper, A New Approach for Material Characterization to Predict Casing Behavior for High-Temperature Geothermal Applications, at the SPE Thermal Well Integrity and Production Symposium for applications up to 500°C (932°F). This paper, authored by Emmanuel Desdoit, Pierre Mauger and Julien Patou, highlights the pioneering research supporting geothermal applications up to 500°C (932°F). Below are the key tests conducted and insights gained from this groundbreaking study.
Pioneering Research for High-Temperature Geothermal
The technical paper focuses on evaluations of L80 materials at elevated temperatures, up to 500°C (932°F), offering groundbreaking insights into material behavior under extreme conditions. These findings build on Vallourec’s existing technologies validated for temperatures up to 350°C (662°F) and represent a significant step toward enabling operations at even higher temperatures.
Using advanced testing and simulation techniques, Vallourec has characterized the behavior of carbon steel grades such as L80 in these extreme conditions. Key aspects of the research include:
- Tensile and Cyclic Tests: Conducted at temperatures ranging from ambient to 500°C (932°F), these tests monitor the evolution of mechanical properties and quantify creep-induced stress relaxation under cyclic loading.
- Elasto-Viscoplastic Material Law: Derived from experimental data, this law enhances the simulation of threaded connections under extreme thermo-mechanical cycles.
- Simulation Results: Implemented in ABAQUS® software, the improved models predict connection behaviors more accurately, uncovering new structural and functional failure modes consistent with field feedback.
Key Findings: Insights into High-Temperature Performance
The research highlights several crucial discoveries regarding the behavior of L80 steel in geothermal environments:
Material Degradation at High Temperatures
L80 steel demonstrates a marked decrease in yield and tensile strength as temperatures rise, especially beyond 350°C (662°F). Cyclic loading tests also revealed stress relaxation and softening effects, with creep becoming more pronounced above this threshold.
Enhanced Connection Simulations
The enhanced material model reliably replicates L80 steel’s behavior under laboratory conditions. Connection simulations using this model reveal new structural and functional failure modes, aligning closely with field feedback from geothermal applications.
Practical Implications for Development
These advanced models enable more accurate predictions of connection performance, supporting faster product validation through interpolated FEA (Finite Element Analysis) between tested sizes. They also provide valuable insights for R&D on higher-temperature applications.
These findings are instrumental in advancing the development of materials and connections capable of meeting the rigorous demands of higher-temperature geothermal wells.
Looking Ahead
Building on these promising results, Vallourec is expanding its research to validate VAM® 21 product lines for use in higher temperature environments and to explore the behavior of other steel grades. This work reinforces Vallourec’s commitment to delivering innovative solutions that accelerate geothermal development and support the energy transition.
For a deeper understanding of these advancements, contact a Vallourec representative for a copy of the technical paper. Together, we can harness the potential of high-temperature geothermal energy to shape a sustainable energy future.
