Hydrogeochemical characterization of leaking carbon dioxide-charged fault zones in east-central Utah

Researchers investigate CO2-rich subsurface systems for reasons ranging from the disposal of CO2 to assessing the risks of encountering CO2 accumulations during petroleum and natural gas exploration. This study presents an overview of data collection techniques needed to accurately characterize CO2 systems, and characterizes the hydrogeochemistry of two fault zones in east-central Utah that leak CO2 to the surface through abandoned oil wells, springs, and geysers. The CO2-rich groundwaters leak from a faulted, plunging anticline. Carbon and helium isotopic data point to an inorganic CO2 source, possibly clay-carbonate reactions that occurred during the burial of the Colorado Plateau. Subsequent uplift may have facilitated the formation of a free CO2 gas phase that could migrate and accumulate.