Feb 05, 2020 · Crystallization of carbonates is a key process affecting the operation of geothermal facilities and aquifer heat storage systems. The crystals formed in an aquifer heat storage test in the Upper Jurassic carbonate aquifer were investigated at injection temperatures of 65,^{circ }hbox {C} to 110,^{circ }hbox {C}, with varying hbox {CO}_{2} .