Geothermochemical

Geothermochemical is an interdisciplinary field that studies the chemical processes associated with geothermal systems, including fluids, rocks, and minerals at elevated temperatures and pressures. It brings together geochemistry, geology, and thermodynamics to understand fluid–rock interaction, mineral precipitation, gas emissions, and heat transport in subsurface reservoirs as well as surface manifestations such as hot springs and fumaroles.

The scope includes hydrothermal systems, reservoir geochemistry, alteration halos, scaling and corrosion, tracer studies, and the numerical modeling of geochemical equilibria and reaction kinetics. Researchers collect field samples of reservoir and produced waters, gases, and mineral precipitates, then analyze them with techniques such as ion chromatography, inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray diffraction (XRD), and isotope analyses. Geochemical modeling tools (for example PHREEQC) are used to compute speciation, saturation indices, and reaction paths.

Applications include optimizing geothermal energy extraction, predicting and mitigating scaling and corrosion, guiding exploration and reservoir management, and assessing environmental impacts of fluid reinjection and gas emissions. Isotope and trace element studies help reconstruct fluid sources, temperatures, and mixing processes within geothermal systems.

Key phenomena studied are water–rock interaction, mineral precipitation (including silica, calcite, and clays), alteration halos around fractures, redox and sulfur chemistry, and gas equilibria. The field supports sustainable geothermal development by providing chemical diagnostics for reservoir monitoring, resource assessment, and environmental stewardship.