To qualify, a proposed well site must have the appropriate geology, with a deep reservoir of porous rock that can accommodate carbon dioxide molecules sitting below a layer of nonporous “cap rock” like shale.
Is this criteria sufficient? It’s a bit unclear what they mean by “accommodate carbon dioxide molecules”, but it seems like there is a risk of the CO2 leaking back out.
I’ve heard of some storage plans which use the local geology to turn the CO2 into carbonate minerals, eliminating the risk of rerelease. Obviously, this is highly dependent on the presence of the appropriate minerals, and can’t be deployed everywhere.
What concerns me is that a lot of these efforts seem to be political in nature and are tied to mitigating the inevitable decline in the fossil fuel industry. More often it makes more sense to speed up the use of renewables and dropping the use of fossil fuels. Fossil fuel use still hasn’t peaked. That is mainly driven by China, who are still building new coal and gas electricity plants. However the peak year of fossil fuel use is very near, there is some speculation it may even be this year for oil use. From then on it will be in steady decline, so of course that industry is going to do everything they can to delay.
