Properties and phenonmena relevant to CH4-CO2 replacement in hydrate-bearing sediments

by J. W. Jung, D. Nicolas Espinoza, J. Carlos Santamarina
Year: 2010


Jung, J. W., Espinoza, D., and Santamarina, J. C. (2010). "Properties and phenonmena relevant to CH4-CO2 replacement in hydrate-bearing sediments." Journal of Geophysical Research, Vol. 115


The injection of carbon dioxide, CO2, into methane hydrate‐bearing sediments causes the release of methane, CH4, and the formation of carbon dioxide hydrate, even if global pressure‐temperature conditions remain within the CH4 hydrate stability field. This phenomenon, known as CH4‐CO2 exchange or CH4‐CO2 replacement, creates a unique opportunity to recover an energy resource, methane, while entrapping a greenhouse gas, carbon dioxide. Multiple coexisting processes are involved during CH4‐CO2 replacement, including heat liberation, mass transport, volume change, and gas production among others. Therefore, the comprehensive analysis of CH4‐CO2 related phenomena involves physico‐chemical parameters such as diffusivities, mutual solubilities, thermal properties, and pressure‐ and temperature‐dependent phase conditions. We combine new experimental results with published studies to generate a data set we use to evaluate reaction rates, to analyze underlying phenomena, to explore the pressure‐temperature region for optimal exchange, and to anticipate potential geomechanical implications for CH4‐CO2 replacement in hydrate‐bearing sediments.