Dawid T. Rybak

Experimental investigation of Basalt-CO2 brine interactions at supercritical conditions

Name: Dawid T. Rybak
Primary Supervisor: Prof. Janine L. Kavanagh
Year: 3
Discipline: Earth Science
Presentation type: 3-minute talk
Project Title: Experimental investigation of Basalt-CO₂ brine interactions at supercritical conditions

Abstract:

There is interest to explore hydrothermal systems near magma bodies for geothermal energy extraction as they have the potential to produce higher energy outputs compared to conventional geothermal reservoirs. These high pressure and temperature hydrological systems are of interest because they force hydrothermal fluids to move above their critical point, and this change in state results in a greater capacity for heat transfer per unit volume of fluid.

An important question to answer is what effect magmatic volatiles have on the fluid-rock interactions because magma degassing has the potential to affect the chemical evolution of the fluids being targeted and the geothermal reservoir’s physical properties over time. As CO2 is a major volatile released by degassing magmas, we conducted two flow-through experiments simulating basalt-CO2 brine interactions under supercritical conditions for 42 and 48 days, respectively. Results show the development of alteration fronts in the host rock along the reactor’s depth and changing fluid chemistry through time. These findings show that starting fluid composition strongly influence spatial and temporal evolution of fluid-rock reactions along the fluid’s pathway.