Geochemical Modeling of the Lamotte Formation for Carbon Sequestration in Missouri

Various geochemical reactions that can occur upon CO2\u3einjection into a sandstone formation in Missouri (MO) have been determined. The Geochemist\u27s Workbench modeling program was used to simulate solubility trapping and mineral precipitation storage mechanisms during CO2\u3egeo-sequestration. Modeling was completed for two periods: injection period (10 years) and post injection period (until equilibrium). The amount of CO2\u3estored via solubility trapping ranged from 57 g/kg of free formation water (northeast MO) to 88 g CO2/kg of free formation water (southwest MO) for fresh water of Greene County. Similarly, CO2\u3estored via mineral trapping ranged from 2 g CO2/kg of free formation water (northeast MO) to 12 g CO2/kg of free formation water (southwest MO). Major mineral contributions to CO2\u3estorage were due to precipitation of siderite and dawsonite. Dawsonite becomes very important during long-term sequestration. Studies to quantify the lowest detectable concentrations of a geological tracer, sulfur hexafluoride (SF6) were also carried out. The lowest detected concentration of SF6 was 4.8 parts per trillion