Systems and methods for thermal reach enhancement
A thermal reach enhanced geothermal wellbore is provided. The geothermal wellbore includes a wellbore extending from a topside surface to a target location in a formation. The geothermal wellbore further includes a plurality of fissures that distally extend from the target location into the formation and that are at least partially filled with a compacted high-thermal k material. The compacted high-thermal k material terminates on a proximal end at the target location of the wellbore and is thermally coupled to a high-thermal conductivity grout or slurry through which heat is conducted to a working fluid that is contained in a closed loop working fluid conduit embedded in the grout or slurry.
1 . A method of extracting heat from a formation, comprising:
placing a closed loop working fluid conduit in a wellbore having a target location in a formation, wherein the formation is a formation with low or no permeability;
pumping a high-thermal conductivity slurry into an annular space between a wall of the wellbore and an outer surface of the closed loop working fluid conduit, wherein the closed loop working fluid conduit is thermally coupled to the high-thermal conductivity slurry;
compacting the high-thermal conductivity slurry to form a compacted high-thermal conductivity composition;
wherein the compacted high-thermal conductivity composition has a decreased water content in an amount of at least 10 wt. % as compared to the high-thermal conductivity slurry prior to compaction, and/or an increased density in an amount of at least 10 wt. % as compared to the high-thermal conductivity slurry prior to compaction;
wherein the compacted high-thermal conductivity composition in the annular space contacts a high-thermal k material in the formation;
wherein the high-thermal k material is disposed in a plurality of fissures in the formation and wherein the fissures extend from the wellbore into the formation; and
transferring heat from the formation via the high-thermal k material in the fissures and the compacted high-thermal conductivity composition to a working fluid in the closed loop working fluid conduit.
2 . The method of claim 1 , wherein the high-thermal k material is a formation compressed material.
3 . The method of claim 1 , wherein the high-thermal k material is a non-cementitious material.
4 . The method of claim 1 , wherein the high-thermal k material is a non-cementitious formation-compressed material.
5 . The method of claim 1 , wherein the high-thermal k material has a size distribution that spans across at least 2 log units.
6 . The method of claim 1 , wherein the high-thermal k material comprises sand, quartz silica, boron nitride, brass, a brass alloy, chrome nickel steel, carbon steel, stainless steel, a transition metal, a transition metal alloy, a post-transition metal, a post-transition metal alloy, an alkaline earth metal alloy, copper, aluminum nitride, and/or silicon carbide.
7 . The method of claim 1 , wherein the high-thermal k material comprises graphite powder, exfoliated graphite, flaked graphite, pyrolytic graphite, desulfurized petroleum coke, fly ash, graphene, and/or carbon nanotubes.
8 . The method of claim 1 , wherein the compacted high-thermal k material has a thermal conductivity of at least 20 W/mK.
9 . The method of claim 1 , wherein the compacted high-thermal conductivity composition is a non-cementitious material.
10 . The method of claim 1 , wherein the compacted high-thermal conductivity composition comprises sand, quartz silica, boron nitride, brass, a brass alloy, chrome nickel steel, carbon steel, stainless steel, a transition metal, a transition metal alloy, a post-transition metal, a post-transition metal alloy, an alkaline earth metal alloy, copper, aluminum nitride, silicon carbide, graphite powder, exfoliated graphite, flaked graphite, pyrolytic graphite, desulfurized petroleum coke, fly ash, graphene, and/or carbon nanotubes.
11 . The method of claim 1 , wherein the compacted high-thermal conductivity composition has a thermal conductivity of at least 20 W/mK.
12 . The method of claim 1 , wherein the fissures extend longitudinally from the wellbore at the target location.
13 . The method of claim 1 , wherein the fissures distally extend from the wellbore at the target location over a distance of between 1 and 25 meter, and/or wherein the fissures have a width of between 5 and 80 mm at a proximal end relative to the wellbore.
14 . A method of extracting heat from a formation, comprising:
placing a closed loop working fluid conduit in a wellbore having a target location in a formation;
pumping a non-cementitious high-thermal conductivity slurry into an annular space between a wall of the wellbore and an outer surface of the closed loop working fluid conduit, wherein the closed loop working fluid conduit is coupled to the high-thermal conductivity slurry;
compacting the high-thermal conductivity slurry to form a compacted non-cementitious high-thermal conductivity composition;
wherein the compacted non-cementitious high-thermal conductivity composition has a decreased water content in an amount of at least 10 wt. % as compared to the high-thermal conductivity slurry prior to compaction, and/or an increased density in an amount of at least 10 wt. % as compared to the high-thermal conductivity slurry prior to compaction
wherein the compacted non-cementitious high-thermal conductivity composition in the annular space contacts a high-thermal k material disposed in a plurality of fissures;
wherein the fissures extend from the wellbore into the formation; and
transferring heat from the formation via the high-thermal k material in the fissures and the compacted non-cementitious high-thermal conductivity composition in the annular space to a working fluid in the closed loop working fluid conduit.
15 . The method of claim 14 , wherein the fissures distally extend from the wellbore at the target location over a distance of between 1 and 25 meter, and/or wherein the fissures have a width of between 5 and 80 mm at a proximal end relative to the wellbore.
16 . The method of claim 14 , wherein the compacted high-thermal conductivity composition and/or the high-thermal k material in the fissures has a thermal conductivity of at least 20 W/mK.
17 . The method of claim 14 , wherein the high-thermal k material has a size distribution that spans across at least 2 log units.
18 . The method of claim 14 , wherein the compacted high-thermal conductivity composition and/or the high-thermal k material comprises sand, quartz silica, boron nitride, brass, a brass alloy, chrome nickel steel, carbon steel, stainless steel, a transition metal, a transition metal alloy, a post-transition metal, a post-transition metal alloy, an alkaline earth metal alloy, copper, aluminum nitride, silicon carbide, graphite powder, exfoliated graphite, flaked graphite, pyrolytic graphite, desulfurized petroleum coke, fly ash, graphene, and/or carbon nanotubes.