Review of Carbonate Rock Experiments at Different Pressure and Temperature Conditions in the Context of Geothermal Energy Exploitation

Geothermal energy exploitation has emerged as a critical solution to combat global climate crises, such as reducing CO2 emissions and climate warming. Scaling is the process of mineral precipitation in fluid pathways and geothermal equipment. It is known to significantly hamper geothermal energy production by decreasing the rates of heat extraction. Numerous research efforts are dedicated to characterising dissolution and precipitation processes, not only to provide know-how for further and safer developments in geothermal energy, but also to adapt such findings to the ever emerging field of geothermal energy recovery. This paper presents an overview of experiments - performed under variable pressure and temperature conditions - with a focus on scaling. We assess the different factors that influence disequilibrium reactions in carbonate rocks, the different experimental setups, and their application to the field. The influence of experimental variables (such as temperature and pressure) on mineral dissolution and precipitation is discussed, and the main learning points from experiments are compared and contrasted. We address techniques for preventing and controlling scaling in geothermal wells based on a comprehensive analysis of experimental studies in carbonate rocks. We propose that the intelligent combination of fieldwork, numerical approaches, and laboratory experience provides a foundation for the success of future work in this field.