Closed well loop for a geothermal system

A closed well loop for a geothermal system, the closed well loop comprising:

• a well that traverses a subterranean formation to extract heat from the subterranean formation, wherein the well includes a vertical section and at least one lateral section that extends laterally and downward away from the vertical section, wherein the at least one lateral section has a toe segment that is located at, or extends to, a depth below a bottom of the vertical section, wherein the vertical section includes an inner pipe, wherein the inner pipe is supported inside an outer pipe in a pipe-in-pipe arrangement, wherein the inner pipe extends to a depth in the vertical section below an intersection of the at least one lateral section and the vertical section, wherein the inner pipe has an interior flow channel, wherein the interior flow channel defines a first flow path for a circulating working fluid, wherein an annulus between the inner pipe and the outer pipe defines a second flow path for the circulating working fluid, wherein the inner pipe includes a thermally-insulative piping system, wherein the thermally-insulative piping system reduces an amount of heat transferred from the circulating working fluid at a higher temperature to the circulating working fluid at a lower temperature, and wherein the circulating working fluid flows in the first flow path and the second flow path within the well;
• an isolation packer disposed within the vertical section, wherein the at least one lateral section intersects the vertical section above the isolation packer;
• and
• at least one lateral injection manifold that extends laterally and downward from the vertical section and intersects the toe segment of a corresponding lateral section, wherein the at least one lateral injection manifold intersects the vertical section below the isolation packer.