Disclosed is a process for manufacturing underground caverns suitable in one embodiment for storage of large volumes of gaseous or liquid materials. The method is an acid dissolution process that can be utilized to form caverns in carbonate rock formations. The caverns can be used to store large quantities...http://www.google.com.au/patents/US7156579?utm_source=gb-gplus-sharePatent US7156579 - Manufactured caverns in carbonate rock
