Viscosified treatment fluids comprising scleroglucan or diutan and associated methods

Abstract

The present invention relates to viscosified treatment fluids comprising gelling agents that comprise scleroglucan or diutan, and their use in industrial and oil field operations. In certain embodiments, the present invention provides methods of treating a portion of a subterranean formation with a viscosified treatment comprising a gelling agent that comprises scleroglucan or diutan. Methods of fracturing, gravel packing, and producing hydrocarbons also are provided. Viscosified treatment fluid compositions and methods of making such exemplary compositions are provided as well.

1 . A method of treating a portion of a subterranean formation comprising the steps of: 
 providing a viscosified treatment fluid that comprises a gelling agent that comprises diutan;    treating the portion of the subterranean formation; and    reducing the viscosity of the viscosified treatment fluid using a breaker that comprises a peroxide.    
     
     
         2 . The method of  claim 1  wherein the breaker is present in an amount sufficient to reduce the viscosity of the viscosified treatment fluid so as to facilitate the recovery of the fluid at the surface.  
     
     
         3 . The method of  claim 1  wherein the peroxide is present in an amount of from about 0.1 to about 10 gallons of peroxide per 1000 gallons of the viscosified treatment fluid.  
     
     
         4 . The method of  claim 1  wherein the viscosified treatment fluid comprises fresh water, salt water, or a brine.  
     
     
         5 . The method of  claim 1  wherein the viscosified treatment fluid comprises a monovalent brine.  
     
     
         6 . The method of  claim 1  wherein the viscosified treatment fluid comprises a salt.  
     
     
         7 . The method of  claim 6  wherein the salt comprises potassium chloride, sodium bromide, ammonium chloride, cesium formate, potassium formate, sodium formate, sodium nitrate, calcium bromide, zinc bromide, or sodium chloride.  
     
     
         8 . The method of  claim 1  wherein the viscosified treatment fluid comprises a pH control additive, a surfactant, a bactericide, a crosslinker, a fluid loss control additive, or a combination thereof.  
     
     
         9 . The method of  claim 8  wherein the pH control additive comprises a chelating agent, a base, an acid, a combination of a chelating agent and an acid, or a combination of a chelating agent and a base.  
     
     
         10 . The method of  claim 1  wherein the breaker comprises tert-butyl hydroperoxide or tert-amyl hydroperoxide.  
     
     
         11 . The method of  claim 1  wherein the breaker comprises encapsulated breaker particles that comprise a breaker and a coating material.  
     
     
         12 . The method of  claim 11  wherein the coating material comprises a degradable polymeric material.  
     
     
         13 . The method of  claim 12  wherein the degradable polymeric material is a polysaccharide, a chitin, a chitosan, a protein, an aliphatic polyester, a poly(lactide), a poly(glycolide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a poly(anhydride), an aliphatic polycarbonate, an orthoester, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), a polyphosphazene, or a combination thereof.  
     
     
         14 . The method of  claim 1  wherein the viscosified treatment fluid comprises an activator or a retarder that is compatible with the breaker.  
     
     
         15 . The method of  claim 14  wherein the retarder comprises sodium thiosulfate.  
     
     
         16 . The method of  claim 1  wherein the viscosified treatment fluid comprises a stabilizer.  
     
     
         17 . The method of  claim 16  wherein the stabilizer comprises sodium thiosulfate.  
     
     
         18 . A method of reducing the viscosity of a viscosified treatment fluid that comprises a gelling agent that comprises diutan comprising contacting the viscosified treatment fluid with a breaker that comprises a peroxide.  
     
     
         19 . The method of  claim 18  wherein the breaker is present in an amount sufficient to reduce the viscosity of the viscosified treatment fluid so as to facilitate the recovery of the fluid at the surface.  
     
     
         20 . The method of  claim 18  wherein the peroxide is present in an amount of from about 0.1 to about 10 gallons of peroxide per 1000 gallons of the viscosified treatment fluid.  
     
     
         21 . The method of  claim 18  wherein the breaker comprises tert-butyl hydroperoxide or tert-amyl hydroperoxide.  
     
     
         22 . The method of  claim 18  wherein the breaker comprises encapsulated breaker particles that comprise a breaker and a coating material.  
     
     
         23 . The method of  claim 22  wherein the coating material comprises a degradable polymeric material.  
     
     
         24 . The method of  claim 23  wherein the degradable polymeric material is a polysaccharide, a chitin, a chitosan, a protein, an aliphatic polyester, a poly(lactide), a poly(glycolide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a poly(anhydride), an aliphatic polycarbonate, an orthoester, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), a polyphosphazene, or a combination thereof.  
     
     
         25 . A method of making a viscosified treatment fluid comprising diutan comprising the step of dissolving diutan in an aqueous fluid to form a viscosified treatment fluid comprising diutan.  
     
     
         26 . The method of  claim 25  wherein the aqueous fluid comprises a salt.  
     
     
         27 . The method of  claim 25  wherein the aqueous fluid comprises potassium chloride.  
     
     
         28 . The method of  claim 25  wherein the aqueous fluid is a 20% potassium chloride solution.  
     
     
         29 . The method of  claim 25  wherein the viscosified treatment fluid comprising diutan has a density in the range of from about 8.4 pounds per gallon to about 20.5 pounds per gallon.  
     
     
         30 . A method of placing a gravel pack in a portion of a subterranean formation comprising: 
 providing a viscosified gravel pack fluid comprising gravel and a gelling agent that comprises diutan;    contacting the portion of the subterranean formation with the viscosified gravel pack fluid so as to place a gravel pack in or near a portion of the subterranean formation; and    reducing the viscosity of the viscosified gravel pack fluid with a breaker comprising a peroxide.    
     
     
         31 . The method of  claim 30  wherein the breaker is present in an amount sufficient to reduce the viscosity of the viscosified treatment fluid so as to facilitate the recovery of the fluid at the surface.  
     
     
         32 . The method of  claim 30  wherein the peroxide is present in an amount of from about 0.1 to about 10 gallons of peroxide per 1000 gallons of the viscosified treatment fluid.  
     
     
         33 . The method of  claim 30  wherein the breaker comprises tert-butyl hydroperoxide or tert-amyl hydroperoxide.  
     
     
         34 . The method of  claim 30  wherein the breaker comprises encapsulated breaker particles that comprise a breaker and a coating material.  
     
     
         35 . The method of  claim 34  wherein the coating material comprises a degradable polymeric material.  
     
     
         36 . The method of  claim 35  wherein the degradable polymeric material is a polysaccharide, a chitin, a chitosan, a protein, an aliphatic polyester, a poly(lactide), a poly(glycolide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a poly(anhydride), an aliphatic polycarbonate, an orthoester, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), a polyphosphazene, or a combination thereof.  
     
     
         37 . The method of  claim 30  wherein the viscosified gravel pack fluid has a density of about 8.4 pounds per gallon to about 20.5 pounds per gallon.  
     
     
         38 . The method of  claim 30  wherein the subterranean formation has a temperature of about 200° F. or higher.  
     
     
         39 . The method of  claim 30  wherein the breaker is present in an amount sufficient to reduce the viscosity of the viscosified gravel pack fluid to facilitate the recovery of the fluid.  
     
     
         40 . A method of fracturing a portion of a subterranean formation comprising: 
 providing a viscosified fracturing fluid comprising a gelling agent that comprises diutan;    contacting the portion of the subterranean formation with the viscosified fracturing fluid at a sufficient pressure to create or enhance at least one fracture in the subterranean formation; and    reducing the viscosity of the viscosified fracturing fluid with a breaker comprising a peroxide.    
     
     
         41 . The method of  claim 40  wherein the viscosified fracturing fluid comprises proppant.  
     
     
         42 . The method of  claim 40  wherein the breaker is present in an amount sufficient to reduce the viscosity of the viscosified treatment fluid so as to facilitate the recovery of the fluid at the surface.  
     
     
         43 . The method of  claim 40  wherein the peroxide is present in an amount of from about 0.1 to about 10 gallons of peroxide per 1000 gallons of the viscosified treatment fluid.  
     
     
         44 . The method of  claim 40  wherein the breaker comprises tert-butyl hydroperoxide or tert-amyl hydroperoxide.  
     
     
         45 . The method of  claim 40  wherein the breaker comprises encapsulated breaker particles that comprise a breaker and a coating material.  
     
     
         46 . The method of  claim 45  wherein the coating material comprises a degradable polymeric material.  
     
     
         47 . The method of  claim 46  wherein the degradable polymeric material is a polysaccharide, a chitin, a chitosan, a protein, an aliphatic polyester, a poly(lactide), a poly(glycolide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a poly(anhydride), an aliphatic polycarbonate, an orthoester, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), a polyphosphazene, or a combination thereof.  
     
     
         48 . The method of  claim 40  wherein the viscosified gravel pack fluid has a density of about 8.4 pounds per gallon to about 20.5 pounds per gallon.  
     
     
         49 . The method of  claim 40  wherein the subterranean formation has a temperature of about 200° F. or higher.  
     
     
         50 . The method of  claim 40  wherein the viscosified fracturing fluid further comprises a fluid loss control additive.  
     
     
         51 . The method of  claim 40  wherein the viscosified treatment fluid comprises a pH control additive, a surfactant, a bactericide, a crosslinker, a fluid loss control additive, a stabilizer, or a combination thereof.  
     
     
         52 . A method of servicing or completing a portion of a subterranean formation comprising: 
 providing a viscosified treatment fluid comprising a gelling agent that comprises scleroglucan; and    servicing or completing at least a portion of the subterranean formation with the viscosified treatment fluid.    
     
     
         53 . The method of  claim 52  wherein servicing or completing at least a portion of the subterranean formation involves stimulating at least a portion of the subterranean formation.  
     
     
         54 . The method of  claim 52  further comprising reducing the viscosity of the viscosified treatment fluid with a breaker after treating the portion of the subterranean formation.  
     
     
         55 . The method of  claim 54  wherein the breaker comprises encapsulated breaker particles that comprise a breaker and a coating material.  
     
     
         56 . The method of  claim 55  wherein the coating material comprises a degradable polymeric material.  
     
     
         57 . The method of  claim 56  wherein the degradable polymeric material is a polysaccharide, a chitin, a chitosan, a protein, an aliphatic polyester, a poly(lactide), a poly(glycolide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a poly(anhydride), an aliphatic polycarbonate, an orthoester, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), a polyphosphazene, or a combination thereof.  
     
     
         58 . The method of  claim 52  wherein the viscosified treatment fluid further comprises a surfactant, a breaker, a bactericide, a crosslinker, a pH control additive, a stabilizer, or a fluid loss control additive.  
     
     
         59 . The method of  claim 52  wherein the viscosified treatment fluid further comprises a salt.  
     
     
         60 . The method of  claim 57  wherein the pH control additive comprises a chelating agent, a base, an acid, a combination of a chelating agent and an acid, or a combination of a chelating agent and a base.  
     
     
         61 . The method of  claim 57  wherein the viscosified treatment fluid further comprises an activator or a retarder.  
     
     
         62 . A method of fracturing a portion of a subterranean formation comprising: 
 providing a viscosified fracturing fluid comprising a gelling agent that comprises scleroglucan; and    contacting the portion of the subterranean formation with the viscosified fracturing fluid at a sufficient pressure to create or enhance at least one fracture in the subterranean formation.    
     
     
         63 . A method of producing hydrocarbons from a subterranean formation wherein a viscosified treatment fluid comprising a gelling agent that comprises scleroglucan is used in a completion or a servicing operation.  
     
     
         64 . A method of producing hydrocarbons from a subterranean formation wherein a viscosified treatment fluid comprising a gelling agent that comprises diutan is used and the subterranean formation has a temperature greater than or equal to 200° F.  
     
     
         65 . A method of producing hydrocarbons from a subterranean formation wherein a viscosified treatment fluid comprising a gelling agent that comprises diutan and a breaker that comprises a peroxide are used.  
     
     
         66 . A subterranean well treatment system comprising a viscosified treatment fluid that comprises diutan and a breaker that comprises a peroxide breaker.  
     
     
         67 . The system of  claim 66  wherein the breaker comprises tert-butyl hydroperoxide or tert-amyl hydroperoxide  
     
     
         68 . The system of  claim 66  wherein at least a portion of the breaker is encapsulated by a coating.  
     
     
         69 . The system of  claim 68  wherein the coating comprises a polysaccharide, a chitin, a chitosan, a protein, an aliphatic polyester, a poly(lactide), a poly(glycolide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a poly(anhydride), an aliphatic polycarbonate, an orthoester, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), a polyphosphazene, or a combination thereof.  
     
     
         70 . The system of  claim 66  wherein the breaker is present in an amount sufficient to reduce the viscosity of the viscosified treatment fluid to facilitate the recovery of the fluid.  
     
     
         71 . The system of  claim 66  wherein the viscosified treatment fluid comprises fresh water, salt water, or a brine.  
     
     
         72 . The system of  claim 66  wherein the viscosified treatment fluid comprises a monovalent brine.  
     
     
         73 . The system of  claim 66  wherein the viscosified treatment fluid comprises a salt.  
     
     
         74 . The system of  claim 66  wherein the viscosified treatment fluid comprises a pH control additive, a surfactant, a bactericide, a crosslinker, a fluid loss control additive, proppant, gravel, or a combination thereof.  
     
     
         75 . A subterranean well servicing or completion fluid comprising a gelling agent that comprises scleroglucan.  
     
     
         76 . The composition of  claim 75  wherein the subterranean well servicing or completion fluid comprises proppant.  
     
     
         77 . The composition of  claim 75  wherein the subterranean well servicing or completion fluid further comprises a surfactant, a breaker, a bactericide, a crosslinker, a pH control additive, or a fluid loss control additive.  
     
     
         78 . The composition of  claim 75  wherein the subterranean well servicing or completion fluid comprises fresh water, salt water, or a brine.  
     
     
         79 . The composition of  claim 75  wherein the subterranean well treatment fluid further comprises a salt.  
     
     
         80 . The composition of  claim 79  wherein the salt comprises potassium chloride, sodium bromide, ammonium chloride, cesium formate, potassium formate, sodium formate, sodium nitrate, calcium bromide, zinc bromide, or sodium chloride.  
     
     
         81 . The composition of  claim 76  wherein the pH control additive comprises a chelating agent, a base, an acid, a combination of a chelating agent and an acid, or a combination of a chelating agent and a base.  
     
     
         82 . A method of making a treatment fluid comprising a scleroglucan gelling agent comprising: 
 dissolving scleroglucan in water to produce a solution;    neutralizing the solution from a pH of about 13 to one of a pH of less than about 12 to form a viscosified treatment fluid comprising a scleroglucan gelling agent.    
     
     
         83 . The method of  claim 82  wherein the water comprises a salt.  
     
     
         84 . The method of  claim 82  wherein the water has a pH of about 13.  
     
     
         85 . A viscosified treatment fluid made by the method of  claim 82.