Method for forming a geothermal well

A method for exchanging heat between a fluid and a subsurface environment, comprising

• flowing a fluid through a thermally conductive tube disposed in a wellbore loop, the wellbore loop comprising:
• a first wellbore having a substantially linear segment connected to an arcuate segment;
• and
• a second wellbore connected to a terminating end of the arcuate segment, wherein:
• the substantially linear segment has a first end located at a surface and a second end connected to the arcuate segment,
• the second wellbore has a third end located at the surface and a fourth end connected to the terminating end of the arcuate segment,
• a distance between the first end and the third end is less than a distance between the second end and the fourth end,
• the tube and a wellbore loop wall define an annulus therebetween that is filled with a geothermal transfer grout,
• the first wellbore is substantially vertical,
• the second wellbore is substantially linear and angled with respect to vertical, and
• the distance between the first end and the third end is about 0.25 m to about 5 m.

A method for forming a geothermal well, comprising:

• drilling a first substantially linear segment from a first point located at a surface to a second point located in a subsurface environment;
• drilling a second substantially linear segment from a third point located at the surface to a fourth point located in the subsurface environment, the first and second substantially linear segments being separated by a distance to prevent geothermal heat transfer between the first and second substantially linear segments;
• drilling a third arcuate segment from the fourth point to the second point or from the second point to the fourth point, thereby forming a wellbore loop;
• and
• disposing a thermally conductive tube through the wellbore loop, wherein the distance between the first and second substantially linear segments is greater between the second and fourth points than between the first and third points.