Global climate change due to the rise in anthropogenic CO2 concentrations in the atmosphere and resulting necessity for the reduction of CO2 emissions is the general scientific consensus. One method for mitigating CO2 concentrations in the atmosphere is to capture CO2 from its sources and sequester it into the subsurface. However, if the stored CO2 reaches highly permeable conduits such as faults and fractures, CO2 could leak unabated to other formations or to the surface. The addressed eruptive mechanisms are analogues to natural CO2 eruption mechanisms, which are found in CO2-driven cold-water geysers around the world. In this project, phenomenological CO2 leakages from cold-water geysers, springs, and diffusive CO2 transport will be investigated by collecting continuous datasets of in-situ P, T, water chemistry (pH, EC, dissolved oxygen, and total dissolved gas) adjacent to the Little Grand and Salt Wash fault systems in Utah. Specific project goals include (1) identification of the original CO2 sourcing and (2) the causes of cyclic patterns observed at cold-water geysers and diffusive soil CO2 flux. In addition, (3) the role of fault systems on these cold-water geysers and soil CO2 flux patterns will be investigated. Part I of the project specifically focuses on understanding the eruption characteristics of CO2-driven cold-water geysers (Crystal and Tenmile geysers). Part II focuses on characterizing the short (daily)- and long-term (month) variations of diffusive soil CO2 flux on the fault systems. In Part III, the numerical simulations will be conducted to validate the dynamic setting of CO2 eruption at the geysers and diffusive CO2 flux from soils.
The project involves societal issues of the importance of CO2 flux, which is considered to be the most critical component for global climate change and the carbon cycle. Understanding CO2-driven cold-water geyser eruptions will be important in the next decade for testing the feasibility of safe storage of the sequestered CO2. Specifically, the advanced understanding of thermophysical changes in cold-water geyser eruptions will help design the operational and reservoir conditions preventing the potential catastrophic CO2 leakage from the storage formation and develop the in-situ optimum sensors to track the subsurface CO2 plume migration at the engineered geologic CO2 storage site. Finally, scientific communities who study hot-water geyser eruption, the well blow-out processes in the petroleum field, and volcanology eruptions will be interested in finding similarities of eruption patterns/periods and the role of CO2.
