Bacteria-based and enzyme-based mechanisms and products for viscosity reduction breaking of viscoelastic fluids

Abstract

It has been discovered that fluids viscosified with viscoelastic surfactants (VESs) may have their viscosities reduced (gels broken) by the direct or indirect action of a biochemical agent, such as bacteria, fungi, and/or enzymes. The biochemical agent may directly attack the VES itself, or some other component in the fluid that produces a by-product that then causes viscosity reduction. The biochemical agent may disaggregate or otherwise attack the micellar structure of the VES-gelled fluid. The biochemical agent may produce an enzyme that reduces viscosity by one of these mechanisms. A single biochemical agent may operate simultaneously by two different mechanisms, such as by degrading the VES directly, as well as another component, such as a glycol, the latter mechanism in turn producing a by-product (e.g. an alcohol) that causes viscosity reduction. Alternatively, two or more different biochemical agents may be used simultaneously. In a specific, non-limiting instance, a brine fluid gelled with an amine oxide surfactant can have its viscosity broken with bacteria such as Enterobacter colacae, Pseudomonas fluorescens, Pseudomonas aeruginosa , and the like.

1 - 32 . (canceled)  
   
   
       33 . An aqueous fluid comprising: 
 water;    at least one viscoelastic surfactant (VES) in an amount effective to increase the viscosity of the aqueous fluid;    at least one biochemical agent in an amount effective to reduce the viscosity of the gelled aqueous fluid, where the biochemical agent is selected from the group consisting of bacteria, fungi, enzymes, and combinations thereof, where the biochemical agent reduces the viscosity of the gelled aqueous fluid by disaggregating or rearranging a micelle structure of the VES.    
   
   
       34 . (canceled)  
   
   
       35 . The fluid of  claim 33  where the biochemical agent is a bacteria type that digests the VES directly.  
   
   
       36 . The fluid of  claim 33  where the biochemical agent is selected from the group consisting of bacteria, fungi, and mixtures thereof, that have been bio-technically engineered by a technique selected from the group consisting of growth challenge, culture for selective gene expression, genetic modification through gene splicing techniques, and combinations thereof.  
   
   
       37 . The fluid of  claim 33  where the biochemical agent is selected from the group consisting of bacteria and fungi that digests a component of the fluid other than the VES to produce a by-product that in turn degrades the VES surfactant.  
   
   
       38 . The fluid of  claim 33  where the component is selected from the group consisting of alcohols, monoalcohol polymers, alcohol fatty acids, alkyl fatty acids, glycols, starches, potassium formate or other formate, polysaccharides, sugars, sugar chelants, sugar alcohols, aliphatic alcohols, reservoir crude oils, proteins, VES stabilizers, amino acids, acetates, phosphonates, phospholipids, lactates, isocyanates, esters, turpenes, butyrates, propionates, salicylates, hexaonates, nitrilotriacetic acid, ethylenediaminetetra-acetic acid, amino chelant compounds, polyaspartates, pyrrolidone compounds, and mixtures thereof.  
   
   
       39 . The fluid of  claim 37  where the by-product is an enzyme selected from the group of enzymes that (a) catalyze a reaction to break down the VES directly, and (b) catalyze a reaction utilizing another component of the fluid other than VES to produce a by-product that in turn degrades the VES surfactant.  
   
   
       40 . The fluid of  claim 39  where the enzyme is lipase.  
   
   
       41 . The fluid of  claim 33  where the VES is selected from the group consisting of amines, amine salts, quaternary ammonium salts, amidoamine oxides and amine oxides.  
   
   
       42 . The fluid of  claim 33  where the VES is tallow amido propylamine oxide (TAPAO).  
   
   
       43 . The fluid of  claim 33  where the VES is erucyl bis-(2-hydroxyethyl)methyl ammonium chloride.  
   
   
       44 . The fluid of  claim 33  where the biochemical agent is bacteria selected from the group consisting of the classes  Enterobacter, Enterococcus, Pseudomonas, Bacillus, Leptospirillum, Clostridium, Arthrobacter, Rhodobacter, Rhodococcus, Micrococcus, Serratia, Thermoanaerobacter, Thiobacillus, Pyrococcus, Lactobacillus, Achromobacter, Propionibacterium, Thermomicrobium, Nitrobacter, Nitrosomonas, Sulfolobus, Methanobacterium, Methanococcus, Bacteroides, Fusobacterium, Syntrophus, Acetogenium, Actinomyces, Acetobacter, Citrobacter, Alteromonas, Acinetobacter, Flavobacterium, Corynebacterium , and mixtures thereof.  
   
   
       45 . The fluid of  claim 33  where the biochemical agent is bacteria selected from the group consisting of  Arthrobacter globiformis, Enterobacter colacae, Lactobacillus sporogenes, Lactobacillus bulgaricus, Lactobacillus acidophillus, Pseudomonas fluorescens, Pseudomonas aeruginosa, Actinomyces israeli, Pseudomonas putida, Nitrobacter vulgaris, Arthrobactor  M153B,  Bacillus megaterium, Thiobacillus novellus, Bacillus subtilis, Bacillus licheniformis, Clostridium pasteurianum, Corynebacterium glucuronolyticum, Enterococcus faecalis Pyrococcus abyssi, Rhodococcus  ST-5 , Rhodococcus  33,  Rhodococcus  H13-A,  Thermoanaerobacter ethanolicus, Thermoanaerobacter mathranii, Nitrosomonas europaea, Propionibacterium propionicus, Rhodobacter sphaeriodes, Clostridium thermocellum, Clostridium  ATCC #53797,  Clostridium  ATCC #53793,  Corynebacterium hydrocarbolastus, Acetomicrobium flavidum, Acetobacter pasteurianus, Serratia marcescens, Acetobacter aceti, Achromobacter xylosoxidans,  and mixtures thereof.  
   
   
       46 . The fluid of  claim 33  where the microbe metabolic activity of the biochemical agent can be enhanced by a parameter selected from the group consisting of temperature, pressure, pH adjustment of the fluid to between about 2.0 and 11.0, and combinations thereof.  
   
   
       47 . The fluid of  claim 33  where the amount of biochemical agent ranges from about 0.01 to about 20.0 percent by volume based on the total volume of fluid.  
   
   
       48 . An aqueous fluid comprising 
 water;    at least one viscoelastic surfactant (VES), in an amount effective to increase the viscosity of the aqueous fluid; and    bacteria, in an amount effective to reduce the viscosity of the gelled aqueous fluid after the viscosity of the aqueous fluid has been increased, where the bacteria reduces the viscosity of the gelled aqueous fluid by disaggregating or rearranging a micelle structure of the VES.    
   
   
       49 . The fluid of  claim 48  where the VES is selected from the group consisting of amines, amine salts, quaternary ammonium salts, and amine oxides.  
   
   
       50 . The fluid of  claim 48  where the VES is tallow amido propylamine oxide (TAPAO).  
   
   
       51 . The fluid of  claim 48  where the bacteria is selected from the group consisting of  Arthrobacter globiformis, Enterobacter colacae, Lactobacillus sporogenes, Lactobacillus bulgaricus, Lactobacillus acidophillus, Pseudomonas fluorescens, Pseudomonas aeruginosa, Actinomyces israeli, Pseudomonas putida, Nitrobacter vulgaris, Arthrobactor  M153B,  Bacillus megaterium, Thiobacillus novellus, Bacillus subtilis, Bacillus licheniformis, Clostridium pasteurianum, Corynebacterium glucuronolyticum, Enterococcus faecalis, Pyrococcus abyssi, Rhodococcus  ST-5 , Rhodococcus  33,  Rhodococcus  H13A,  Thermoanaerobacter ethanolicus, Thermoanaerobacter mathranii, Nitrosomonas europaea, Propionibacterium propionicus, Rhodobacter sphaeriodes, Clostridium thermocellum, Clostridium  ATCC #53797,  Clostridium  ATCC #53793,  Corynebacterium hydrocarbolastus, Acetomicrobium flavidum, Acetobacter pasteurianus, Serratia marcescens, Acetobacter aceti, Achromobacter xylosoxidans , and mixtures thereof.  
   
   
       52 . The fluid of  claim 48  where the bacteria has been bio-technically engineered by a technique selected from the group consisting of growth challenge, culture for selective gene expression, genetic modification through gene splicing techniques, and combinations thereof.  
   
   
       53 . The fluid of  claim 48  where the bacteria is a type that attacks the VES directly.  
   
   
       54 . The fluid of  claim 48  where the amount of bacteria present ranges from about 0.01 to about 20.0 percent by volume based on the total volume of fluid.  
   
   
       55 . The fluid of  claim 48  where the microbe metabolic activity of the bacteria can be enhanced by a parameter selected from the group consisting of temperature, pressure, pH adjustment of the fluid to between about 2.0 and 11.0, and combinations thereof.