Silica-encapsulated tracers suitable for use in tracing fracturing fluid in subsurface formations are described herein. More specifically. described herein is an improved method of encapsulating tracers for reduced adsorption on a rock material, as well as less caustic methods for releasing the encapsulated tracers using ammonium hydroxide or other weak base as an etching agent. as an alternative to using highly corrosive reagents such as hydrofluoric acid.

A liquid suspension composition for wellbore operations can include a diutan gum, a viscosifier, and a carrier fluid, wherein the diutan gum is suspended in the liquid suspension composition to form a suspended diutan gum. A wellbore servicing fluid can include the liquid suspension composition, and methods of making and using the wellbore servicing fluid.

A guar gum fracturing fluid gel and a guar gum fracturing fluid system with reduced pH dependence, a preparation method and an application thereof are disclosed. The fracturing fluid gel includes 0.01-0.2% of nanomaterial, 0.1-0.5% of guar gum, 0.1-0.5% of organic boron-titanium crosslinker and a remaining amount of water. The fracturing fluid gel is more stable in network structure, tolerant of different temperatures and has good shear resistance. A preparation method and an application of the fracturing fluid gel are also provided. In the guar gum fracturing fluid system, the dependence on pH level is reduced, thereby alleviating the damage caused by a high pH value to a reservoir.

The present discloses a mussel biomimetic heat-resistant and salt-tolerant thickener and a preparation method therefor, a gel fracturing fluid and a preparation method and use thereof.

A process for on-site biopolymer production related to enhanced oil recovery consisting of bacterium/fungus activation with selected substrates by placing them in a sterile, solid culture medium and incubating at a temperature until reaching a desired polysaccharide production level; performing a replication sequence is performed in a sterile, liquid culture medium to increase the amount of biomass to obtain a laboratory inoculum; fermenting in fermentation vats or bioreactors, where substrates are transformed by microorganisms into biopolymers and biomass; filtration or centrifugation, causing the biopolymer to separate from the biomass; a liquid polymer obtained is mixed with injection water in a static mixer, and then injected directly into a reservoir through an injection well.

A method is provided for improved degradation of metal-crosslinked polymer gels, which are useful in oil and gas treating operations. In this method a polysaccharide having a higher degree of substitution than the polymer in the polymer gel is added to the gel. The polysaccharide removes the crosslinking metal ion from the gel to thus break down the gel and reduce its viscosity.

Improved hydraulic fracturing compositions are disclosed which help reduce potential negative environmental impact by hydraulic fracturing. The disclosed compositions have flammability and toxicity and are relatively safe for the environment. The compositions may also contain biodegradable components.

A method is provided for improved degradation of metal-crosslinked polymer gels, which are useful in oil and gas treating operations. In this method a polysaccharide having a higher degree of substitution than the polymer in the polymer gel is added to the gel. The polysaccharide removes the crosslinking metal ion from the gel to thus break down the gel and reduce its viscosity.

Improved hydraulic fracturing compositions are disclosed which help reduce potential negative environmental impact by hydraulic fracturing. The disclosed compositions have flammability and toxicity and are relatively safe for the environment. The compositions may also contain biodegradable components.

Provided are water-soluble polymers that may include a water-soluble bipolymer, a water-soluble anionic terpolymer, and a water-soluble cationic terpolymer. The water-soluble polymers may include a reaction product of a first monomer that has a vinyl-containing group linked to a pendant carbohydrate moiety; a second monomer that has a vinyl group, a carbonyl group and a nitrogen; an anionic monomer in a water-soluble anionic terpolymer; and a cationic monomer in a water-soluble cationic terpolymer. Further provided are aqueous solutions that may include a water-soluble bipolymer, a water-soluble anionic terpolymer, and a water-soluble cationic terpolymer. Further provided are methods of use that may include introducing an aqueous solution into a formation such that the formation fractures, where the aqueous solution may include a water-soluble bipolymer, a water-soluble anionic terpolymer, and a water-soluble cationic terpolymer.