Treatment fluids and methods of use in subterranean formations

Abstract

The present invention relates to subterranean treatment operations, and more particularly to improved bridging agents comprising a degradable material, improved subterranean treatment fluids comprising such improved bridging agents, and methods of using such improved subterranean treatment fluids in subterranean formations. An example of a method of the present invention is a method of drilling a well bore in a subterranean formation. Another example of a method of the present invention is a method of forming a self-degrading filter cake in a subterranean formation. Another example of a method of the present invention is a method of degrading a filter cake in a subterranean formation. An example of a composition of the present invention is a treatment fluid including a viscosifier, a fluid loss control additive, and a bridging agent comprising a degradable material. Another example of a composition of the present invention is a bridging agent comprising a degradable material.

1 . A method of drilling a well bore in a subterranean formation, comprising the step of drilling a well bore in a subterranean formation using a treatment fluid comprising a base fluid, a viscosifier, a fluid loss control additive, and a bridging agent that comprises a degradable material.  
     
     
         2 . The method of  claim 1  further comprising the step of permitting the bridging agent to form a filter cake in the well bore.  
     
     
         3 . The method of  claim 2  wherein the step of permitting the bridging agent to form a filter cake in the well bore comprises forming the filter cake upon a surface in the formation.  
     
     
         4 . The method of  claim 2  further comprising the step of permitting the filter cake to degrade.  
     
     
         5 . The method of  claim 1  wherein the base fluid comprises an organic fluid.  
     
     
         6 . The method of  claim 5  wherein the organic fluid comprises a mineral oil, a synthetic oil, or an ester.  
     
     
         7 . The method of  claim 6  wherein the organic fluid is kerosene or diesel.  
     
     
         8 . The method of  claim 1  wherein the base fluid is present in the treatment fluid in an amount sufficient to form a pumpable treatment fluid.  
     
     
         9 . The method of  claim 8  wherein the base fluid is present in the treatment fluid in an amount in the range of from about 20% to about 99% by volume of the treatment fluid.  
     
     
         10 . The method of  claim 1  wherein the viscosifier comprises an organophilic clay, a synthetic oil-soluble polymer, or a polymeric fatty acid.  
     
     
         11 . The method of  claim 10  wherein the viscosifier is an organophilic clay.  
     
     
         12 . The method of  claim 1  wherein the viscosifier is present in the treatment fluid in an amount sufficient to provide a desired degree of solids suspension.  
     
     
         13 . The method of  claim 1  wherein the viscosifier is present in the treatment fluid in an amount in the range of from about 1 to about 20 pounds viscosifier per barrel of treatment fluid.  
     
     
         14 . The method of  claim 1  wherein the fluid loss control additive comprises a synthetic oil-soluble polymer, a powdered hydrocarbon resin, or organophilic lignite.  
     
     
         15 . The method of  claim 1  wherein the fluid loss control additive is a synthetic, oil-soluble polymer.  
     
     
         16 . The method of  claim 1  wherein the fluid loss control additive is present in the treatment fluid in an amount sufficient to provide a desired degree of fluid loss control.  
     
     
         17 . The method of  claim 1  wherein the fluid loss control additive is present in the treatment fluid in an amount in the range of from about 1 to about 30 pounds of fluid loss control additive per barrel of treatment fluid.  
     
     
         18 . The method of  claim 1  wherein the bridging agent is present in the treatment fluid in an amount sufficient to create an efficient filter cake.  
     
     
         19 . The method of  claim 1  wherein the bridging agent is present in the treatment fluid in an amount in the range of from about 0.1% to about 32% by weight of the treatment fluid.  
     
     
         20 . The method of  claim 1  wherein the degradable material comprises a polysaccharide, a chitin, a chitosan, a protein, an orthoester, an aliphatic polyester, a poly(glycolide), a poly(lactide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a polyanhydride, an aliphatic polycarbonate, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), or a polyphosphazene.  
     
     
         21 . The method of  claim 1  wherein the degradable material further comprises a plasticizer or a stereoisomer of a poly(lactide).  
     
     
         22 . The method of  claim 1  wherein the degradable material comprises poly(lactic acid).  
     
     
         23 . The method of  claim 22  wherein the poly(lactic acid) is present in the degradable material in a stoichiometric amount.  
     
     
         24 . The method of  claim 1  wherein the degradable material comprises a degradable aliphatic polyester and a hydrated organic or inorganic compound.  
     
     
         25 . The method of  claim 24  wherein the hydrated organic or inorganic compound comprises sodium acetate trihydrate, L-tartaric acid disodium salt dihydrate, sodium citrate dihydrate, sodium tetraborate decahydrate, sodium hydrogen phosphate heptahydrate, sodium phosphate dodecahydrate, amylose, a starch-based hydrophilic polymer, or a cellulose-based hydrophilic polymer.  
     
     
         26 . The method of  claim 24  wherein the degradable aliphatic polyester is present in the degradable material in a stoichiometric amount.  
     
     
         27 . The method of  claim 26  wherein the hydrated organic or inorganic compound is present in the degradable material in a stoichiometric amount.  
     
     
         28 . The method of  claim 24  wherein the degradable aliphatic polyester is poly(lactic acid).  
     
     
         29 . The method of  claim 24  wherein the degradable material further comprises calcium carbonate.  
     
     
         30 . The method of  claim 4  wherein the bridging agent does not begin to degrade until at least about 12 hours after its placement in the subterranean formation.  
     
     
         31 . The method of  claim 1  wherein the treatment fluid further comprises a weighting agent, a salt, an emulsifier, a filtration control agent, and a pH control agent.  
     
     
         32 . The method of  claim 4  wherein the base fluid is an organic fluid, present in the treatment fluid in an amount in the range of from about 20% to about 99% by volume of the treatment fluid; wherein the fluid loss control additive is a synthetic, oil-soluble polymer, present in the treatment fluid in an amount in the range of from about 1 to about 30 pounds fluid loss control additive per barrel of treatment fluid; wherein the viscosifier is present in the treatment fluid in an amount in the range of from about 1 to about 20 pounds per barrel of treatment fluid; wherein the bridging agent is present in the treatment fluid in an amount in the range of from about 0.1% to about 32% by weight of the treatment fluid; and wherein the degradable material comprises a degradable aliphatic polyester and a hydrated organic or inorganic compound.  
     
     
         33 . A method of forming a self-degrading filter cake in a subterranean formation, comprising the steps of: 
 placing a treatment fluid in a subterranean formation, the treatment fluid comprising a base fluid, a viscosifier, a fluid loss control additive, and a bridging agent that comprises a degradable material; and    permitting the bridging agent to form a self-degrading filter cake upon a surface in the formation, whereby fluid loss to the formation through the self-degrading filter cake is reduced.    
     
     
         34 . The method of  claim 33  wherein the step of permitting the bridging agent to form a filter cake in the well bore comprises forming the filter cake upon a surface in the formation itself.  
     
     
         35 . The method of  claim 33  wherein the base fluid comprises an organic fluid.  
     
     
         36 . The method of  claim 35  wherein the organic fluid comprises a mineral oil, a synthetic oil, or an ester.  
     
     
         37 . The method of  claim 36  wherein the organic fluid is kerosene or diesel.  
     
     
         38 . The method of  claim 33  wherein the base fluid is present in the treatment fluid in an amount in the range of from about 20% to about 99% by volume of the treatment fluid.  
     
     
         39 . The method of  claim 33  wherein the viscosifier is present in the treatment fluid in an amount in the range of from about 1 to about 20 pounds viscosifier per barrel of treatment fluid.  
     
     
         40 . The method of  claim 33  wherein the fluid loss control additive is present in the treatment fluid in an amount in the range of from about 1 to about 30 pounds fluid loss control additive per barrel of treatment fluid.  
     
     
         41 . The method of  claim 33  wherein the bridging agent is present in the treatment fluid in an amount in the range of from about 0.1% to about 32% by weight of the treatment fluid.  
     
     
         42 . The method of  claim 33  wherein the degradable material comprises poly(lactic acid).  
     
     
         43 . The method of  claim 33  wherein the degradable material comprises a degradable aliphatic polyester and a hydrated organic or inorganic compound.  
     
     
         44 . The method of  claim 43  wherein the degradable aliphatic polyester is poly(lactic acid).  
     
     
         45 . The method of  claim 33  wherein the base fluid is an organic fluid, present in the treatment fluid in an amount in the range of from about 20% to about 99% by volume of the treatment fluid; wherein the fluid loss control additive is a synthetic, oil-soluble polymer, present in the treatment fluid in an amount in the range of from about 1 to about 30 pounds fluid loss control additive per barrel of treatment fluid; wherein the viscosifier is present in the treatment fluid in an amount in the range of from about 1 to about 20 pounds per barrel of treatment fluid; wherein the bridging agent is present in the treatment fluid in an amount in the range of from about 0.1% to about 32% by weight of the treatment fluid; and wherein the degradable material comprises a degradable aliphatic polyester and a hydrated organic or inorganic compound.  
     
     
         46 . A method of degrading a filter cake in a subterranean formation, the filter cake having been deposited therein by a treatment fluid comprising a bridging agent, comprising the steps of: 
 utilizing a bridging agent comprising a degradable material; and    permitting the degradable material to degrade.    
     
     
         47 . The method of  claim 46  wherein the treatment fluid further comprises a base fluid, a viscosifier, and a fluid loss control additive.  
     
     
         48 . The method of  claim 47  wherein the base fluid comprises an organic fluid.  
     
     
         49 . The method of  claim 48  wherein the organic fluid comprises a mineral oil, a synthetic oil, or an ester.  
     
     
         50 . The method of  claim 49  wherein the organic fluid is kerosene or diesel.  
     
     
         51 . The method of  claim 46  wherein the base fluid is present in the treatment fluid in an amount in the range of from about 20% to about 99% by volume of the treatment fluid.  
     
     
         52 . The method of  claim 47  wherein the viscosifier is present in the treatment fluid in an amount in the range of from about 1 to about 20 pounds per barrel of treatment fluid.  
     
     
         53 . The method of  claim 47  wherein the fluid loss control additive is present in the treatment fluid in an amount in the range of from about 1 to about 30 pounds fluid loss control additive per barrel of treatment fluid.  
     
     
         54 . The method of  claim 46  wherein the bridging agent is present in the treatment fluid in an amount in the range of from about 0.1% to about 32% by weight of the treatment fluid.  
     
     
         55 . The method of  claim 46  wherein the degradable material comprises poly(lactic acid).  
     
     
         56 . The method of  claim 46  wherein the degradable material comprises a degradable aliphatic polyester and a hydrated organic or inorganic compound.  
     
     
         57 . The method of  claim 56  wherein the degradable aliphatic polyester is poly(lactic acid).  
     
     
         58 . The method of  claim 47  wherein the base fluid is an organic fluid, present in the treatment fluid in an amount in the range of from about 20% to about 99% by volume of the treatment fluid; wherein the fluid loss control additive is a synthetic, oil-soluble polymer, present in the treatment fluid in an amount in the range of from about 1 to about 30 pounds fluid loss control additive per barrel of treatment fluid; wherein the viscosifier is present in the treatment fluid in an amount in the range of from about 1 to about 20 pounds per barrel of treatment fluid; wherein the bridging agent is present in the treatment fluid in an amount in the range of from about 0.1% to about 32% by weight of the treatment fluid; and wherein the degradable material comprises a degradable aliphatic polyester and a hydrated organic or inorganic compound.  
     
     
         59 . A treatment fluid comprising a viscosifier, a fluid loss control additive, and a bridging agent comprising a degradable material.  
     
     
         60 . The treatment fluid of  claim 59  further comprising a base fluid.  
     
     
         61 . The treatment fluid of  claim 60  wherein the base fluid comprises an organic fluid.  
     
     
         62 . The treatment fluid of  claim 61  wherein the organic fluid comprises a mineral oil, a synthetic oil, or an ester.  
     
     
         63 . The treatment fluid of  claim 62  wherein the organic fluid is kerosene or diesel.  
     
     
         64 . The treatment fluid of  claim 60  wherein the base fluid is present in an amount sufficient to form a pumpable treatment fluid.  
     
     
         65 . The treatment fluid of  claim 64  wherein the base fluid is present in an amount in the range of from about 20% to about 99% by volume of the treatment fluid.  
     
     
         66 . The treatment fluid of  claim 65  wherein the viscosifier comprises an organophilic clay, a synthetic, oil-soluble polymer, or a polymeric fatty acid.  
     
     
         67 . The treatment fluid of  claim 66  wherein the viscosifier is an organophilic clay.  
     
     
         68 . The treatment fluid of  claim 59  wherein the viscosifier is present in an amount sufficient to provide a desired degree of solids suspension.  
     
     
         69 . The treatment fluid of  claim 68  wherein the viscosifier is present in an amount in the range of from about 1 to about 20 pounds viscosifier per barrel of treatment fluid.  
     
     
         70 . The treatment fluid of  claim 59  wherein the fluid loss control additive comprises a synthetic, oil-soluble polymer, a powdered hydrocarbon resin, or organophilic lignite.  
     
     
         71 . The treatment fluid of  claim 70  wherein the fluid loss control additive is a synthetic, oil-soluble polymer.  
     
     
         72 . The treatment fluid of  claim 59  wherein the fluid loss control additive is present in an amount sufficient to provide a desired degree of fluid loss control.  
     
     
         73 . The treatment fluid of  claim 71  wherein the fluid loss control additive is present in an amount in the range of from about 1 to about 30 pounds per barrel of treatment fluid.  
     
     
         74 . The treatment fluid of  claim 59  wherein the bridging agent comprising the degradable material is present in an amount sufficient to create an efficient filter cake.  
     
     
         75 . The treatment fluid of  claim 74  wherein the bridging agent is present in an amount in the range of from about 0.1% to about 32% by weight of the treatment fluid.  
     
     
         76 . The treatment fluid of  claim 59  wherein the degradable material comprises a polysaccharide, a chitin, a chitosan, a protein, an orthoester, an aliphatic polyester, a poly(glycolide), a poly(lactide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a polyanhydride, an aliphatic polycarbonate, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), or a polyphosphazene.  
     
     
         77 . The treatment fluid of  claim 59  wherein the degradable material further comprises a plasticizer or a stereoisomer of a poly(lactide).  
     
     
         78 . The treatment fluid of  claim 59  wherein the degradable material comprises  
     
     
         79 . The treatment fluid of  claim 78  wherein the poly(lactic acid) is present in the degradable material in a stoichiometric amount.  
     
     
         80 . The treatment fluid of  claim 59  wherein the degradable material comprises a degradable aliphatic polyester and a hydrated organic or inorganic compound.  
     
     
         81 . The treatment fluid of  claim 80  wherein the hydrated organic or inorganic compound comprises sodium acetate trihydrate, L-tartaric acid disodium salt dihydrate, sodium citrate dihydrate, sodium tetraborate decahydrate, sodium hydrogen phosphate heptahydrate, sodium phosphate dodecahydrate, amylose, a starch-based hydrophilic polymer, or a cellulose-based hydrophilic polymer.  
     
     
         82 . The treatment fluid of  claim 80  wherein the degradable aliphatic polyester is present in the degradable material in a stoichiometric amount.  
     
     
         83 . The treatment fluid of  claim 80  wherein the hydrated organic or inorganic compound is present in the degradable material in a stoichiometric amount.  
     
     
         84 . The treatment fluid of  claim 80  wherein the degradable aliphatic polyester is poly(lactic acid).  
     
     
         85 . The treatment fluid of  claim 80  wherein the degradable material further comprises calcium carbonate.  
     
     
         86 . The treatment fluid of  claim 59  wherein the bridging agent does not begin to degrade until at least about 12 hours after it has been placed in a subterranean formation.  
     
     
         87 . The treatment fluid of  claim 59  wherein the treatment fluid further comprises a weighting agent, a salt, an emulsifier, a filtration control agent, and a pH control agent.  
     
     
         88 . The treatment fluid of  claim 59  wherein the base fluid is an organic fluid, present in the treatment fluid in an amount in the range of from about 20% to about 99% by volume of the treatment fluid; wherein the fluid loss control additive is an oil-soluble polymer, present in the treatment fluid in an amount in the range of from about 1 to about 30 pounds fluid loss control additive per barrel of treatment fluid; wherein the viscosifier is present in the treatment fluid in an amount in the range of from about 1 to about 20 pounds per barrel of treatment fluid; wherein the bridging agent is present in the treatment fluid in an amount in the range of from about 0.1% to about 32% by weight of the treatment fluid; and wherein the degradable material comprises a degradable aliphatic polyester and a hydrated organic or inorganic compound.  
     
     
         89 . A bridging agent comprising a degradable material.  
     
     
         90 . The bridging agent of  claim 89  wherein the degradable material comprises a polysaccharide, a chitin, a chitosan, a protein, an orthoester, an aliphatic polyester, a poly(glycolide), a poly(lactide), a poly(ε-caprolactone), a poly(hydroxybutyrate), a polyanhydride, an aliphatic polycarbonate, a poly(orthoester), a poly(amino acid), a poly(ethylene oxide), or a polyphosphazene.  
     
     
         91 . The bridging agent of  claim 89  wherein the degradable material comprises poly(lactic acid).