Multicomponent vs. Classical Geothermometry: An Evaluation using Reactive Transport Modeling

Reactive transport simulations were used to examine the chemical evolution of deep geothermal fluids as they ascend to the surface, and to assess constraints on the application of solute geothermometers. Al and Mg concentrations of deep fluids are sensitive to precipitation-dissolution processes, affecting reservoir temperatures estimated with multicomponent geothermometry. The concentrations of major elements such as Na, K, and SiO2 are less sensitive to reequilibration, and thus geothermometers based on these elements are often reliable, but fail when dilution or mixing with saline waters occurs. For these cases, multicomponent geothermometry coupled with optimization provides a more reliable approach to reconstruct the fluid composition at depth and estimate reservoir temperatures.