Microemulsions, mesophase surfactant and micellar solutions, and in situ-formed fluids formulated with high density brine

A method of removing at least a portion of hydrocarbons and synthetic oils from a subterranean location containing hydrocarbons and synthetic oils, the method comprising:

• introducing a fluid formulation to the subterranean location to contact the fluid formulation with the hydrocarbons and synthetic oils present at the subterranean location, where the fluid formulation comprises a set of components selected from the group consisting of:
• (1) a mesophase surfactant solution and/or micellar solution,
• which comprises:
• at least one surfactant;
• at least one linker;
• and
• a high-density brine comprising a salt;
• (2) a single-phase microemulsion (SPME), which comprises:
• at least one surfactant;
• at least one non-polar fluid;
• at least one linker;
• a co-surfactant or co-solvent;
• and
• a high-density brine comprising a salt;
• and
• (3) in situ fluid-forming components comprising:
• at least one surfactant;
• at least one linker;
• a co-surfactant or co-solvent;
• and
• a high-density brine comprising a salt;
• incorporating at least part of the hydrocarbons and synthetic oils into an incorporating fluid selected from the group consisting of (1) the mesophase surfactant solution and/or the micellar solution, (2) the SPME, and (3) a different fluid formed in situ at the subterranean location, where in the latter case the method further comprises forming the different fluid in situ from the in situ fluid-forming components and the different in situ-formed fluid is selected from the group consisting of microemulsions, nanoemulsions, macroemulsions, miniemulsions, swollen micellar dispersion, multiple emulsions, and combinations thereof;
• and
• removing the incorporating fluid incorporating the non-polar material from the subterranean location;
• where the at least one linker is selected from the group consisting of amines, carboxylic acids, dicarboxylic acids, saturated and unsaturated fatty acids, alcohols with more than 8 carbon atoms, glycols, polyols, phenols, toluene sulfonate, and combinations thereof, and the at least one linker is different from the at least one surfactant;
• and
• where the high-density brine has a density higher than 15 lb/gal up to about 21 lb/gal (higher than 1800 up to about 2500 kg/m3);
• where the salt is selected from formate salts, chloride salts, bromide salts, acetate salts, nitrate salts, phosphate salts, citrate salts, tartrate salts, iodide salts, glutamate salts, diglutamate salts, nitriloacetate salts, and combinations thereof.

A method of removing at least a portion of hydrocarbons and synthetic oils from a subterranean location containing hydrocarbons and synthetic oils, the method comprising:

• introducing a fluid formulation to the subterranean location to contact the fluid formulation with the hydrocarbons and synthetic oils present at the subterranean location, where the fluid formulation comprises a set of components selected from the group consisting of:
• (1) a mesophase surfactant solution and/or micellar solution,
• which comprises:
• at least one surfactant;
• at least one linker;
• and
• a high-density brine comprising a salt;
• (2) a single-phase microemulsion (SPME), which comprises:
• at least one surfactant;
• at least one non-polar fluid;
• at least one linker;
• and
• a high-density brine comprising a salt;
• and
• (3) in situ fluid-forming components comprising:
• at least one surfactant;
• at least one linker;
• and
• a high-density brine comprising a salt;
• incorporating at least part of the hydrocarbons and synthetic oils into an incorporating fluid selected from the group consisting of (1) the mesophase surfactant solution and/or the micellar solution, (2) the SPME, and (3) a different fluid formed in situ at the subterranean location , where in the latter case the method further comprises forming the different fluid in situ from the in situ fluid-forming components and the different in situ-formed fluid is selected from the group consisting of microemulsions, nanoemulsions, macroemulsions, miniemulsions, swollen micellar dispersion, multiple emulsions, and combinations thereof;
• and
• removing the incorporating fluid incorporating the non-polar material from the subterranean location;
• where the at least one linker is selected from the group consisting of amines, carboxylic acids, dicarboxylic acids, saturated and unsaturated fatty acids, alcohols with more than 8 carbon atoms, glycols, polyols, phenols, toluene sulfonate, and combinations thereof, and the at least one linker is different from the at least one surfactant and where the concentration of the linker in the SPME or the in situ-formed SPME ranges from about 0.1 vol % to about 5 vol %;
• where the high-density brine has a density higher than 15 lb/gal up to about 21 lb/gal (higher than 1800 up to about 2500 kg/m3);
• and
• where the incorporating fluid is a thermodynamically stable, macroscopically homogeneous mixture of at least four components, where the four components are:
• a polar phase from the polar fluid, a non-polar phase from the hydrocarbons and synthetic oils, the at least one linker, and the at least one surfactant.