Methods and systems for increasing heat transfer in geothermal systems

A method for heat transfer between a subsurface and a downhole heat exchanger inserted in a wellbore, the method comprising:

• pumping a first volume of a slurry into the wellbore and into one or more fractures:
• wherein pumping the first volume of the slurry comprises using a pump-hold-relax technique until volume and pressure stabilize within the wellbore, and
• wherein the first volume of the slurry comprises:
• a quantity of a quantity of a material having a high thermal conductivity configured to transfer heat,
• a quantity of a proppant configured to prop open one or more fractures, and
• a quantity of a slurrying agent configured to suspend the quantity of the thermally conductive material within the quantity of the slurrying agent,
• wherein the first volume of the slurry is configured to:
• preserve permeability within the one or more fractures;
• and
• facilitate a transfer of heat;
• and
• inserting a closed-loop geothermal system into the wellbore to from an augmented closed-loop geothermal system,
• wherein the augmented closed-loop geothermal system comprises a fluid conduit and the downhole heat exchanger fluidly connected to the fluid conduit.

A system of increasing heat transfer between a downhole heat exchanger and a subsurface, the system comprising:

• a wellbore extending from a surface and penetrating the subsurface;
• a slurry pumping system configured to pump a first volume of slurry into one or more fractures,
• wherein the first volume of slurry comprises:
• a quantity of a quantity of a material having a high thermal conductivity configured to transfer heat;
• a quantity of a proppant configured to prop open the one or more fractures;
• and
• a quantity of a slurrying agent configured to suspend the quantity of the thermally conductive material within the quantity of the slurrying agent,
• wherein the first volume of the slurry is configured to:
• be pumped into the wellbore using a pump-hold-relax technique until volume and pressure stabilize within the wellbore,
• preserve permeability within the one or more fractures, and facilitate a transfer of heat;
• a closed-loop geothermal system configured to transfer heat from the downhole heat exchanger to an uphole heat exchanger, the closed-loop geothermal system comprising:
• a working fluid configured to transfer heat,
• the uphole heat exchanger configured to transfer heat from the working fluid,
• the downhole heat exchanger disposed within the wellbore and configured to transfer heat to the working fluid, and
• a fluid conduit fluidly connected to the uphole heat exchanger and the downhole heat exchanger,
• wherein the fluid conduit comprises a closed-loop flow path and configured to transport the working fluid between the uphole heat exchanger and the downhole heat exchanger;
• and
• a completions system configured to insert the downhole heat exchanger and the fluid conduit into the wellbore to form an augmented closed-loop geothermal system with the slurry.

A system of increasing heat transfer between a subsurface and a downhole heat exchanger during operation, the system comprising:

• a wellbore extending from a surface and penetrating the subsurface;
• a closed-loop geothermal system configured to transfer heat from the downhole heat exchanger to an uphole heat exchanger, the closed-loop geothermal system comprising:
• a working fluid configured to transfer heat,
• the uphole heat exchanger configured to transfer heat from the working fluid,
• the downhole heat exchanger disposed within the wellbore and configured to transfer heat to the working fluid, and
• a fluid conduit fluidly connected to the uphole heat exchanger and the downhole heat exchanger,
• wherein the fluid conduit comprises a closed-loop flow path and configured to transport the working fluid between the uphole heat exchanger and the downhole heat exchanger;
• one or more fractures within the subsurface and filled, at least partially, with a proppant and a quantity of a material having a high thermal conductivity sufficient to form a thermally conductive pathway configured to transfer heat from the subsurface to the downhole heat exchanger forming an augmented closed-loop geothermal system,
• wherein the one or more fractures were created using a pump-hold-relax technique until volume and pressure stabilize within the wellbore;
• and
• a heat utilization facility configured to operate the downhole heat exchanger and comprising:
• an uphole heat exchanger configured to extract heat energy from a hot working fluid;
• and
• a turbine operatively connected to the fluid conduit and configured to generate electrical power, wherein the turbine is operatively connected to the uphole heat exchanger.