The CO2 bubble volume fraction, eruption velocity, flash depth and mass emission of CO2 were determined from multiple wellbore CO2-driven cold-water geysers (Crystal and Tenmile geysers, in Utah and Chimayó geyser in New Mexico). At shallow depths the bubble volume fraction ranges from 0 to 0.8, eruption velocities range from 2 to 20 m/s and flash depths are predominately shallow ranging from 5 to 40 m below the surface. Annual emission of CO2 is estimated to be (4.77±1.92)×103, (6.17±1.73)×101, (6.54±0.57)×101t/yr for Crystal, Tenmile and Chimayó geysers, respectively. These estimates are coherent with Burnside et al. (2013) showing that the rate of CO2 leakage from wellbores is greater than fault-parallel or diffuse CO2 leakage. The geyser plumbing geometry consists of a vertical wellbore which allows for the upward migration of CO2-rich fluids due to artesian conditions. The positive feedback system of a CO2-driven eruption occurs within the well. Active inflow of CO2 into the regional aquifers through faulted bedrock allows geysering to persist for decades. Crystal geyser erupts for over 24 h at a time, highlighting the potential for a wellbore in a natural environment to reach relatively steady-state high velocity discharge. Mitigating high velocity CO2-driven discharge from wellbores will, however, be easier than mitigating diffuse leakage from faults or into groundwater systems.
Bibliographical noteFunding Information:
All financial support for this research was provided by the NSF ( EAR-1246404 ), R&D Project on Environmental Management of Geologic CO 2 Storage (Project Number 2014001810004 ) funded by the Korea Environmental Industry & Technology Institute and the U.S. DOE ZERT Project . Thanks to Jim Roberts for allowing access and analysis of his geysering well. Thanks to Jason Norman, Nancy Kanjorski, Jack Graham and Cheng Thao for their help with data collection. We appreciate constructive comments from Dr. Shaul Hurwitz and one anonymous reviewer.
All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science