Abstract: Disclosed are compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using polymer viscosified fluid crosslinked with metal complexes with amino and/or phosphonic acids to provide an increased crosslinking temperature and a low pH sensitivity. The metal complexes can be used with borate crosslinkers to provide continuous viscosification as the temperature is increased.

Abstract: Disclosed are compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using polymer viscosified fluid crosslinked with metal complexes with amino and/or phosphonic acids to provide an increased crosslinking temperature and a low pH sensitivity. The metal complexes can be used with borate crosslinkers to provide continuous viscosification as the temperature is increased.

Abstract: 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.

Abstract: Disclosed are compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using polymer viscosified fluid crosslinked with metal complexes with amino and/or phosphonic acids to provide an increased crosslinking temperature and a low pH sensitivity. The metal complexes can be used with borate crosslinkers to provide continuous viscosification as the temperature is increased.

Abstract: Process fluids comprising more than 1 wt % polyacrylamide and a non-metallic crosslinker may be used to control lost circulation in subterranean wells. The process fluid is placed into a subterranean lost-circulation zone and allowed to crosslink, thereby forming a gel barrier that limits further flow of process fluid into the zone. The non-metallic crosslinker may preferably comprise one or more polylactams. A pH-adjusting agent may also be incorporated into the process fluid.

Abstract: The invention provides a method comprising providing a composition comprising a pH trigger and a polymer able to be hydrated in a defined pH zone; injecting the composition with a pH outside the defined pH zone; triggering the pH trigger to adjust the pH of the composition within the defined pH zone; and allowing viscosity of the composition to increase and form a plug.

Abstract: A technique utilizes micro-tubing to facilitate performance of a well treatment in which the micro-tubing is deployed for cooperation with a larger tubing, such as a coiled tubing positioned in wellbore. The micro-tubing is used to deliver a separated chemical downhole to modify a property of a treatment fluid used in performing a desired well treatment operation at a desired treatment region along the wellbore. A variety of additional components may be combined with the micro-tubing to further facilitate the treatment application.

Abstract: Described is a method for treating a subterranean formation penetrated by a wellbore, the method including the introduction of a well treatment fluid containing at least an encapsulated biocide. Once the encapsulated biocide is introduced and after a predetermined period of time, a biocide is released from an encapsulation material and treats the wellbore and the subterranean formation.

Abstract: The invention provides a method comprising providing a composition comprising a pH trigger and a polymer able to be hydrated in a defined pH zone; injecting the composition with a pH outside the defined pH zone; triggering the pH trigger to adjust the pH of the composition within the defined pH zone; and allowing viscosity of the composition to increase and form a plug.

Abstract: Disclosed herein is a gel comprising, polyacrylamide crosslinked with a non-metallic crosslinker, the non-metallic crosslinker comprising a polyamine. A method of making the gel and a method of using the gel are also disclosed.

Abstract: The invention discloses a method comprising providing a fluid comprising a viscosifying agent in an aqueous medium; contacting the fluid with a N-halogenated derivative of hydantoin; whereby the viscosity of the fluid with the N-halogenated derivative of hydantoin is reduced compared to the viscosity of the fluid alone; and introducing the fluid into a well. The N-halogenated derivative of hydantoin can be dichlorodimethylhydantoin (DCDMH), bromochlorodimethylhydantoin (BCDMH), or dibromodimethylhydantoin (DBDMH). The N-halogenated derivative of hydantoin can be 1,3-Dichloro-5,5-dimethylhydantoin or 1,3-Dibromo-5,5-dimethylhydantoin.

Abstract: The invention discloses a method comprising providing a fluid comprising a viscosifying agent in an aqueous medium; contacting the fluid with a halogenisocyanuric acid or halogenisocyanurate component; whereby the viscosity of the fluid with the halogenisocyanuric acid or halogenisocyanurate component is reduced compared to the viscosity of the fluid alone; and introducing the fluid into a well. The halogenisocyanuric acid component can be mono chloroisocyanuric acid, dichloroisocyanuric acid or trichloroisocyanuric acid. The halogenisocyanurate component can be an alkali metal monochloroisocyanurate, alkali metal dichloroisocyanurate or alkali metal trichloroisocyanurate.

Abstract: A method of treating a subterranean formation penetrated by a wellbore utilizes a treating fluid formed from an aqueous solution of a water-soluble polymer. The treating fluid further contains a crosslinking agent and an optional delayed release alkaline additive. The delayed release alkaline additive may be at least one of urea, a urea derivative, a solid alkaline earth metal carbonate, a solid alkaline earth metal oxide and combinations of these. The treating fluid further includes an acidic pH adjusting agent used in an amount to provide the treating fluid with a pH of less than about 5. The treating fluid is then introduced into the formation.

Abstract: A method of treating a subterranean formation penetrated by a wellbore is accomplished by introducing a fluid into the wellbore containing a combined fluid loss additive and breaker. The combined fluid loss additive and breaker is formed from particles of an organic peroxide provided on a substrate. The particles are sized to facilitate fluid loss control. A treatment operation is carried out wherein a treatment fluid viscosified with a polymer is introduced into the formation through the wellbore.

Abstract: Methods comprising preparing an aqueous mixture of an anionic polymer, a charge screening surfactant, and a borate crosslinker, wherein the mixture has a conductivity less than 10 mS/cm, injecting the mixture down a wellbore, and gelling the mixture. An embodiment of the aqueous mixture can also include tetramethylammonium chloride as a clay stabilizer and a metal crosslinker such as a complex of zirconium and an amino acid ligand system. An embodiment can effectively provide borate crosslinking of an anionic polymer in a low-ionic-strength fluid system, without sacrificing ultimate gel strength or thermal persistence of the metal crosslinked polymer.

Abstract: A well treatment fluid and method uses an organic peroxide. An activator embodiment can lower an effective concentration of the peroxide to break the fluid. A weight ratio of activator:organic peroxide can be at least about 1:20 in one well treatment fluid embodiment. A peroxyester breaker embodiment can be used in a well treatment fluid and method. A breaker delay agent embodiment can control the polymer break window in a well treatment fluid and method using an organic peroxide. A breaker package embodiment used in a well treatment fluid and method can include an organic peroxide and an amine breaker delay agent having the formula RR1NR2 wherein R, R1 and R2 are independently selected from hydrogen, alkyl, hydroxyalkyl, and combinations thereof.

Abstract: The invention relates to novel wellbore treatment methods and fluids using compositions formed from an aqueous medium, a regularly substituted hydrophilically functional polysaccharide having a degree of substitution from about 0.1 to about 0.5, wherein the percent of insoluble polysaccharide is about 10% or less, and a crosslinker. The wellbore treatment fluid is particularly useful for fracturing a subterranean formation penetrated by a wellbore.

Abstract: A well treatment fluid and method uses an organic peroxide. An activator embodiment can lower an effective concentration of the peroxide to break the fluid. A weight ratio of activator:organic peroxide can be at least about 1:20 in one well treatment fluid embodiment. A peroxyester breaker embodiment can be used in a well treatment fluid and method. A breaker delay agent embodiment can control the polymer break window in a well treatment fluid and method using an organic peroxide. A breaker package embodiment used in a well treatment fluid and method can include an organic peroxide and an amine breaker delay agent having the formula RR1NR2 wherein R, R1 and R2 are independently selected from hydrogen, alkyl, hydroxyalkyl, and combinations thereof.

Abstract: Methods comprising preparing an aqueous mixture of an anionic polymer, a charge screening surfactant, and a borate crosslinker, wherein the mixture has a conductivity less than 10 mS/cm, injecting the mixture down a wellbore, and gelling the mixture. An embodiment of the aqueous mixture can also include tetramethylammonium chloride as a clay stabilizer and a metal crosslinker such as a complex of zirconium and an amino acid ligand system. An embodiment can effectively provide borate crosslinking of an anionic polymer in a low-ionic-strength fluid system, without sacrificing ultimate gel strength or thermal persistence of the metal crosslinked polymer.

Abstract: Disclosed are compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using polymer viscosified fluid crosslinked with metal complexes with amino and/or phosphonic acids to provide an increased crosslinking temperature and a low pH sensitivity. The metal complexes can be used with borate crosslinkers to provide continuous viscosification as the temperature is increased.