Why would you think that fracturing using CO2 is a good idea?
Liquid is used to carry the sand. The sand is necessary to hold open the cracks after the fracturing fluid is removed. The fracturing fluid must be removed to allow the oil/gas to flow back out the well head.
Your method, if it could even work, does not sequester the CO2. It would come back out before the production would start. Methods of CO2 flood as described in this article have been used successfully in Texas for many years. CO2 flood leaves the CO2 in the reservoir.
1. Liquid CO2 would carry sand just as easily as any other liquid.
2. CO2 can’t contaminate groundwater.
3. CO2 can be easily separated from the nat gas and reused.
4. Process would use far less water and produce far less liquid waste.