Non-reactive and reactive experiments to determine the electrical conductivities of aqueous geothermal solutions up to supercritical conditions

摘要: Abstract Electrolytes, dissolved in aqueous solutions, have the tendency to associate at near-critical temperature, which causes a removal of free charge carriers from solution. This behavior is intensified “low” pressure range supercritical field and has become noticeable reduction fluid conductivity by an order magnitude. Thus, deep resistivity surveys are regarded provide convenient means for detecting roots geothermal high-enthalpy reservoirs. In previous decades, temperature dependence electrical properties single-component brines been extensively studied up conditions. Very few data available two-component brines, but none multicomponent mixtures, representing natural fluids. we developed flow-through set-up measure both intrinsic hydrothermal solutions effect fluid-solid interactions on conductivities 23–422 °C 31 MPa. Experimental conditions were adapted those two geothermally exploited areas Iceland – Krafla Reykjanes characterized meteoric seawater controlled systems, respectively. Our study shows that mixed exhibit similar left-skewed curve characteristic like single component with decreasing precipitously minimum critical temperature. At further isobaric rise remain this level. The opposite was observed reactive experiments, where solid interaction allowed. case, re-increased factor 7 within seconds, indicating significant immediate increase solubility rock composite materials, contact suggest high reaction kinetics process. However, did not steady fluid-rock systems wide conductivities. competing processes mineral dissolution new formations also evident complementary micro-structural investigations as well chemical analyses percolated