CPC C09K 8/5045 (2013.01) [C04B 14/104 (2013.01); C04B 22/103 (2013.01); E21B 33/14 (2013.01); C04B 2111/70 (2013.01)] | 23 Claims |
1. A method of using a grout fluid, which comprises:
placing a geothermal conduit in at least one hole in the earth;
providing a grout fluid consisting essentially of water and a bentonite-based grout, wherein the bentonite-based grout consists essentially of from about 30 to about 40 weight percent (wt %) calcium carbonate based on a total weight of the bentonite-based grout, a bentonite, one or more grout-setting modifiers, and one or more thermally conductive materials, and excludes cementitious materials that (i) when mixed with a liquid form a plastic paste and harden or (ii) harden under dry conditions;
introducing the grout fluid into a space between the geothermal conduit and sidewalls of the at least one hole so that the grout fluid is in contact with the geothermal conduit;
after introducing the grout fluid, allowing the grout fluid to set to fix the geothermal conduit to the at least one hole, wherein after setting, the grout fluid has a hydraulic conductivity of between about 1×10−7 cm/s and about 1×10−9 cm/s, and
heating or cooling a heat transfer fluid in the geothermal conduit by respectively transferring heat through the set grout fluid from the earth to the heat transfer fluid or vice versa.
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