Not exactly dry ice, it is supercritically pressured carbon dioxide so it has the density of a liquid but defuses like a gas. CO2 plumes are stable at depths where injection occurs because they are maintained in a pressure and temperature environment where the CO2 stays in a liquid stage, so it will never rise to the surface like a conventional lighter-than-air gas. In-situ mineral carbonation can also occur where the CO2 is injected into silicate rock formations to promote carbonate mineral formation, locking the CO2 for thousands (millions maybe) years.
Not exactly dry ice, it is supercritically pressured carbon dioxide so it has the density of a liquid but defuses like a gas. CO2 plumes are stable at depths where injection occurs because they are maintained in a pressure and temperature environment where the CO2 stays in a liquid stage, so it will never rise to the surface like a conventional lighter-than-air gas. In-situ mineral carbonation can also occur where the CO2 is injected into silicate rock formations to promote carbonate mineral formation, locking the CO2 for thousands (millions maybe) years.