Effect of CO2-enriched water on fracture pressure in Sandstone and Shale Rocks

Low-permeability reservoirs play an indispensable role in sustainable energy strategies; a good understanding of fracture behavior is essential. This study uses carbonated water injection for fracture pressure assessment to examine the fracture pressure response of Kentucky Sandstone and Eagle Ford Shale low-permeability rock formations. The Kentucky Sandstone shows porosity levels between 10% to 12% along with 0.98 mD permeability whereas the Eagle Ford Shale exhibits lower porosity at 2.6% combined with 21.39 μD permeability. The core samples received CO2 as complete CO2 dissipation before the start of injection under 900 psi pressure. The obtained results indicated that fracture initiation occurred at a lower pressure in Kentucky Sandstone than Eagle Ford Shale. The pure CO2-based and carbonated water-based fracturing weaken both rocks, but sandstone at a higher rate. The technique of carbonated water is found promising, with the additional benefit that geochemical activity arises due to carbonated water.