Thermosiphoning supercritical CO2 in geothermal energy production

A method for thermosiphoning a working fluid within a geothermal formation comprising:

• providing a geothermal energy system comprising an injection well, an underground hot reservoir, and a production well, wherein the injection well, the reservoir and the production well provide a fluid path;
• heating supercritical CO2 and circulating the supercritical CO2 within the fluid path of the geothermal energy system;
• and
• siphoning the supercritical CO2 in the fluid path by,
• maintaining a low temperature of the supercritical CO2 within the injection well in a range between 50° C. to 200° C.;
• maintaining a high temperature of the supercritical CO2 within the production well in a range between 150° C. to 350° C., where the high temperature of the supercritical CO2 is at least 50° C. greater than the low temperature of the supercritical CO2;
• and
• maintaining a pressure of the supercritical CO2 in the fluid path in a range from 1400 psia to 4000 psia;
• and
• maintaining a supercritical CO2 density ratio of at least 1.5, where the density ratio is the ratio of the density of the CO2 at the low temperature divided by the density of the CO2 at the high temperature, and wherein the density ratio has a peak within the range of the pressure of the supercritical CO2.