System and method for injecting a gas into a subsurface geothermal formation

A system for injecting a gas into a geothermal reservoir, comprising:

• an outer tubular within a wellbore, wherein the outer tubular is configured to inject an aqueous solution;
• and
• an inner tubular within the outer tubular, wherein the inner tubular comprises a closed downhole end and comprises a sparger near the closed downhole end of the inner tubular within the wellbore at a sparger depth from a surface,
• wherein the sparger comprises a plurality of holes,
• wherein the sparger is configured to inject the gas into the aqueous solution via the plurality of holes,
• wherein the inner tubular comprises a pressure regulator above the sparger, the pressure regulator being configured to prevent a backflow to the surface, and
• wherein the sparger depth is between 150 and 1200 meters from the surface, and a reservoir depth of the geothermal reservoir from the surface is greater than the sparger depth.