A High-Pressure High-Temperature Column for the Simulation of Hydrothermal Water Circulation at Laboratory Scale

Modeling the geothermal energy production cycle of a deep geothermal system at laboratory scale is challenging because of high-temperature and pressure conditions. In this work, a high-pressure high-temperature column to simulate production, heat transfer, and reinjection of a geothermal fluid in a fractured rock system is presented. The column includes two independently heated pressure vessels, a heat exchanger, and sensors for temperatures, pressures, flow rate, electric conductivity, and pH value of the circulating fluid at different locations. The presented column enables the quantitative analysis of coupled hydro-thermo-chemical processes in fractured rock cores close to in situ geothermal conditions. Heat extraction and reinjection of geothermal fluids into fractured reservoirs can be reproduced because of the possibility of heating and cooling of the circulating fluid. Further, it is possible to inject a second fluid phase into the column to investigate additional processes, such as mineral precipitation during reinjection. In this work, we present the experimental setup of the column and first results showing the capability of the system.