| Title | Assessing the impact of subsurface uncertainty on CO2-plume geothermal performance |
|---|---|
| Authors | Mohammad Fathy, Graeme Beardsmore, Stuart D.C. Walsh |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Meeting global energy demands while reducing greenhouse gas emissions requires both clean energy sources and carbon management strategies. Geothermal energy is a reliable and renewable resource that provides continuous power and is not affected by weather. At the same time, carbon capture, utilization, and storage (CCUS) technologies are essential for reducing CO2 emissions from industrial activities. One innovative approach that connects these two goals is CO2-Plume Geothermal (CPG) systems, which use captured CO2 as a working fluid to extract heat from the subsurface while also storing the CO2 underground. However, the performance of CPG systems is highly affected by geological uncertainty, such as variations in rock properties and fluid flow behavior. Understanding and quantifying these uncertainties is important for predicting energy output and designing effective geothermal systems. This study investigates the potential of CPG systems using the Egg model, a synthetic reservoir with 100 different permeability realizations. Reservoir simulations were performed using tNavigator to explore how changes in relative permeability, reservoir temperature, and injection temperature, along with uncertain geological parameters, influence key outcomes such as production well temperatures, total energy output, and CO2 breakthrough. These results will also be compared against those from water-based geothermal systems to evaluate the relative performance of CO2 as a working fluid. These results support better decision-making for geothermal development and emphasize the importance of quantifying geological uncertainty when designing and evaluating CPG systems. |