Methods and working fluids for recovering a hydrocarbon material contained within a subterranean formation

1. A method of recovering a hydrocarbon material from a subterranean formation, comprising:

subjecting preliminary substantially solid particles to at least one exfoliation process to form expanded, preliminary substantially solid particles;

attaching functional groups to surfaces of the expanded, preliminary substantially solid particles to form substantially solid particles, the functional groups selected to promote the formation of a substantially stable dispersion of the substantially solid particles within carbon dioxide gas;

forming a working fluid comprising the substantially stable dispersion of the substantially solid particles within the carbon dioxide gas, the substantially solid particles exhibiting a greater heat capacity than the carbon dioxide gas; and

introducing the working fluid into a subterranean formation containing a hydrocarbon material to heat and remove the hydrocarbon material from the subterranean formation.

2. The method of claim 1 , wherein attaching functional groups to surfaces of the expanded, preliminary substantially solid particles comprises selecting the functional groups so that the substantially solid particles exhibit surfactant characteristics.

3. The method of claim 1 , further comprising forming the substantially solid particles to exhibit a surface area within a range of from about 300 m 2 /g to about 1800 m 2 /g.

4. The method of claim 1 , wherein forming a working fluid comprises forming the working fluid to comprise from about 0.05 percent by weight to about 20.0 percent by weight of the substantially solid particles.

5. The method of claim 1 , wherein introducing the working fluid into a subterranean formation comprises introducing the working fluid into the subterranean formation at a temperature within a range of from about 100° C. to about 350° C.

6. The method of claim 1 , further comprising selecting at least some of the substantially solid particles to individually comprise a core of a first material at least partially surrounded by a shell of a second material.

7. A method of recovering a hydrocarbon material from a subterranean formation, comprising:

forming nanoparticles comprising at least one of graphite, graphene, fullerenes, diamond, nanofibers, clay, inorganic material, an organo-silicon material, and metal;

expanding the nanoparticles through one or more of fluorination, Brønsted acid intercalation, and thermal shock treatment;

attaching functional groups to the expanded nanoparticles to form functionalized nanoparticles formulated to remain stably dispersed in carbon dioxide gas at a temperature within a range of from about 100° C. to about 350° C.;

combining the expanded nanoparticles with carbon dioxide gas to form a working fluid; and

injecting the working fluid into a subterranean formation at the temperature within the range of from about 100° C. to about 350° C. to heat and remove a hydrocarbon material contained within the subterranean formation.

8. The method of claim 7 , wherein forming nanoparticles comprises forming the nanoparticles to have a heat capacity of greater than or equal to about 0.1 kJ/kg-K, and to have a thermal conductivity of greater than or equal to about 50 W/m-K.

9. The method of claim 7 , wherein forming nanoparticles comprises forming graphene nanoparticles.