Modeling of CO2 injection into aquifers containing dissolved H2S

In this paper, analytical one-dimensional modeling of CO2 injection into aquifers which contain dissolved H2S is presented. When CO2 is injected into such aquifers, the H2S initially dissolved in the brine will be exsolved and released into CO2 plume. It was shown that depending on reservoir pressure and temperature as well as on initial concentration of H2S the leading edge of CO2 plume may contain 100% H2S which is in free phase. The highly toxic nature of H2S gas suggests the need to account for dissolved H2S in aquifers when establishing risk assessment, monitoring, and management strategies at CO2 storage sites.