Patent ID: 11959666
Assignee: COLORADO SCHOOL OF MINES
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  E  Y | IPC E  F

Claim 19:
20. A method of harvesting geothermal energy in a subterranean formation, comprising:
drilling an injection wellbore that extends into the subterranean formation;
positioning a plurality of selectively opening sleeves in the injection wellbore spaced apart within the subterranean formation, each of said plurality of selectively opening sleeves being actuatable between an open position and a closed position, wherein a set of adjacent selectively opening sleeves of said plurality of selectively opening sleeves are threadably connected to a casing string, and wherein said set of adjacent selectively opening sleeves and said casing string are encased in cement;
fracturing said cement encasing said selectively opening sleeves and fracturing the subterranean formation in a plurality of locations proximate to the plurality of selectively opening sleeves to define a plurality of stages at a plurality of distances from a ground surface and to enhance a fluid flow into the subterranean formation when said plurality of selectively opening sleeves are in the open position;
injecting a fluid down said injection wellbore at a first temperature through a first selectively opening sleeve of said plurality of selectively opening sleeves at a first distance of the plurality of distances in the injection wellbore corresponding to a first stage of the plurality of stages;
closing said first selectively opening sleeve and opening at least a second selectively opening sleeve of said plurality of selectively opening sleeves at a second, different distance of the plurality of distances in the injection wellbore corresponding to a second, different stage of the plurality of stages; and
producing a heated fluid from said at least a second selectively opening sleeve at a second temperature higher than said first temperature.