Novel hyperthermophilic Dictyoglomus beta-mannanases are provided for use in high temperature industrial applications requiring enzymatic hydrolysis of 1,4-β-D-mannosidic linkages in mannans, galactomannans, and glucomannans. Also provided are methods and compositions for fracturing a subterranean formation in which a gellable fracturing fluid is first formed by blending together a hydratable polymer and a Dictyoglomus beta-mannanase as an enzyme breaker. An optimized and stabilized recombinant Dictyoglomus beta-mannanase is provided that shows superior performance/effectiveness and properties in degrading guar and derivatized guars at pH ranges from 3.0 to 12 and temperatures ranging from 130° F. to in excess of 270° F.

A well treatment fluid is disclosed containing water, a crosslinkable component, a crosslinker; and an enzyme breaker containing a cellulase enzyme, the well treatment fluid having a total dissolved solids content of at least about 75,000 mg/L up to about 250,000 mg/L. A method of treating a subterranean formation is also disclosed including placing the well treatment fluid in the subterranean formation. It is also disclosed that the well treatment fluid can be a combination of a first fluid including water, the crosslinkable component, the crosslinker, and the enzyme breaker, and having a total dissolved content A with formation water having a total dissolved content B which is higher than the total dissolved content A of the first fluid.

Dual-purpose additives that may be used as viscosifying agents and surface active agents in fluids, subterranean treatments and oilfield operations are provided. In one embodiment, the methods comprise: providing a treatment fluid comprising a base fluid and a polymeric dual-purpose additive comprising a base polymer comprising a plurality of monomer units, and one or more hydrophobic groups bonded to at least one of the monomer units; introducing the treatment fluid into at least a portion of a subterranean formation; and depolymerizing at least a portion of the dual-purpose additive to form one or more surface active fragments, each of the surface active fragments comprising one or more of the hydrophobic groups bonded to one or more of the monomer units.

Methods of preparing a viscosified treatment fluid comprising a base fluid, a gelling agent, and breaker coated particulates (“BCPs”). The BCPs comprise particulates at least partially coated with a first layer of a stabilization agent followed by a second layer of a breaker. The viscosified treatment fluid may be introduced into a subterranean formation, the breaker activated to reduce a viscosity thereof, and a particulate pack formed in the subterranean formation with the BCPs.

A method of treating a subterranean formation, the method including placing a well treatment fluid comprised of at least an enzyme and a breaker additive in the subterranean formation. Initially, the pH of the well treatment fluid is about 11.5. The breaker additive reduces the pH of the well treatment fluid by at least 1.5 to increase the activity of enzyme and accelerate hydrolysis of a crosslinkable component.

A method for wellbore treatment. The method including preparing an encapsulated treatment agent via polymerization, feeding the encapsulated treatment agent into the wellbore, delivering the encapsulated treatment agent to a desired depth within a formation in the wellbore, activating an acoustic or an electromagnetic source at the desired depth within the formation, and generating an acoustic field or an electromagnetic field. The acoustic field or electromagnetic field activates the encapsulant thereby releasing the treatment agent into the wellbore and a desired depth.

A method of enhancing conductivity within a hydrocarbon-bearing reservoir by building proppant pillars in a spatial arrangement in fractures created or enlarged in the reservoir. Two fluids of differing viscosity and stability are simultaneously pumped into the reservoir. The fluids contain identical proppants which include a proppant which is neutrally buoyant in the fluid and a proppant which is not neutrally buoyant in the fluid. Vertically extending pillars are created within the formation when the fluids are destabilized and the heavier proppant is then released from the destabilized fluids. The area between the pillars may be held open by the presence of the neutrally buoyant proppant in the remaining fluid. Fluid produced from the hydrocarbon-bearing reservoir is then flowed at least partially through channels between the vertically extending pillars.

A method of treating a subterranean formation penetrated by a wellbore, the method comprising pumping a wellbore fluid into the wellbore, the wellbore fluid comprising an aqueous base fluid and an environmentally friendly slurried gelling agent meeting at least two of the following three criteria: (1) Biodegradation: a) >60% in 28 days as measured by OECD 306 or any other OSPAR-accepted marine protocols, b) or in the absence of valid results for such tests: i. >60% in 28 days as measured by OECD 301B, 301C, 301D, 301F, 310, Freshwater BODIS or ii. >70% in 28 days as measured by OECD 301A, 301E); (2) Bioaccumulation: a) a bioconcentration factor of less than 100; b) log P.sub.ow≦3 and molecular weight >700, or c) if the conclusion of a weight of evidence expert judgment under Appendix 3 of OSPAR Agreement 2008-5 is positive; and (3) Aquatic Toxicity: a) LC.sub.50>10 mg/l or EC.sub.50>10 mg/l and performing a downhole operation.

Provided herein is a hydraulic fracturing fluid containing enzyme encapsulated hydrogel nanoparticles and a breaker composition of a viscosifier-degrading enzyme encapsulated in the hydrogel nanoparticle. Also provided are methods for hydraulic fracturing utilizing hydrogel nanoparticles encapsulating an enzyme as a breaker to prevent the premature degradation of the fracturing fluid, to improve transport and placement of the proppant and to facilitate subsequent cleaning of the fracturing fluid.

Discrete, individualized carbon nanotubes having targeted, or selective, oxidation levels and/or content on the interior and exterior of the tube walls can be used for nanotube-mediated controlled delivery of degradative molecules, such as oxidizers and enzymes, for oil-field drilling applications. A manufacturing process using minimal acid oxidation for carbon nanotubes may also be used which provides higher levels of oxidation compared to other known manufacturing processes.