Method for the fracture stimulation of a subterranean formation having a wellbore by using impact-modified thermoset polymer nanocomposite particles as proppants

Abstract

A method for fracture stimulation of a subterranean formation includes providing a thermoset polymer nanocomposite particle precursor composition comprising a polymer precursor mixture, dispersed within a liquid medium, containing at least one of an initiator; at least one of a monomer, an oligomer or combinations thereof, said monomer and oligomer having three or more reactive functionalities capable of creating crosslinks between polymer chains; at least one of an impact modifier; and nanofiller particles substantially dispersed within the liquid medium; subjecting the nanocomposite particle precursor composition to suspension polymerizing conditions; subjecting the resulting nanocomposite particles to heat treatment; forming a slurry comprising a fluid and a proppant that includes the heat-treated nanocomposite particles; injecting the slurry into a wellbore; and emplacing the proppant within a fracture network in the formation.

What is claimed: 
     
         1 . A method for fracture stimulation of a subterranean formation having a wellbore, comprising:
 providing a thermoset polymer nanocomposite particle precursor composition comprising a polymer precursor mixture, dispersed within a liquid medium, containing at least one of an initiator; at least one of a monomer, an oligomer or combinations thereof, said monomer and oligomer having three or more reactive functionalities capable of creating crosslinks between polymer chains; at least one of an impact modifier, said impact modifier comprising from 0.1 to 65 weight percent of the impact modifier, plus the monomer, oligomer, or combinations thereof; and from 0.001 to 60 volume percent of nanofiller particles possessing a length that is less than 0.5 microns in at least one principal axis direction; said nanofiller particles comprising at least one of dispersed fine particulate material, fibrous material, discoidal material, or a combination of such materials, wherein said nano filler particles are substantially dispersed within the liquid medium;   subjecting the nanocomposite particle precursor composition to suspension polymerizing conditions to form the polymeric nanocomposite particle, whereby said nanofiller particles are substantially incorporated into a polymer;   subjecting the resulting nanocomposite particles to heat treatment as a post-polymerizing process;   forming a slurry comprising a fluid and a proppant, wherein said proppant comprises the heat-treated nanocomposite particles, said heat-treated nanocomposite particles being formed from a rigid thermoset polymer matrix;   injecting into the wellbore said slurry at sufficiently high rates and pressures such that said formation fails and fractures to accept said slurry; and   emplacing said proppant within a fracture network in said formation in a packed mass or a partial monolayer of particles, which packed mass or partial monolayer props open the fracture network; thereby allowing produced gases, fluids, or mixtures thereof, to flow towards the wellbore.   
     
     
         2 . The method of  claim 1 , wherein said polymer precursor mixture comprises at least one of monomer, oligomer or combinations thereof; said at least one of monomer, oligomer or combinations thereof being used to synthesize thermoset epoxies, epoxy vinyl esters, polyesters, phenolics, melamine-based resins, polyurethanes, polyureas, polyimides, or mixtures thereof. 
     
     
         3 . The method of  claim 1 , wherein said polymer precursor mixture comprises a crosslinking monomer selected from the group consisting of: Divinylbenzene, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, trimethylolpropane dimethacrylate, trimethylolpropane diacrylate, pentaerythritol tetramethacrylate, pentaerythritol trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, pentaerythritol diacrylate, bisphenol-A diglycidyl methacrylate, ethyleneglycol dimethacrylate, ethyleneglycol diacrylate, diethyleneglycol dimethacrylate, diethyleneglycol diacrylate, triethyleneglycol dimethacrylate, and triethyleneglycol diacrylate, a bis(methacrylamide) having the formula: 
       
         
           
           
               
               
           
         
         a bis(acrylamide) having the formula: 
       
       
         
           
           
               
               
           
         
         a polyolefin having the formula CH 2 ═CH—(CH 2 ) x —CH═CH 2  (wherein x ranges from 0 to 100, inclusive), a polyethyleneglycol dimethylacrylate having the formula: 
       
       
         
           
           
               
               
           
         
         a polyethyleneglycol diacrylate having the formula: 
       
       
         
           
           
               
               
           
         
         a molecule or a macromolecule containing at least three isocyanate (—N═C═O) groups, a molecule or a macromolecule containing at least three alcohol (—OH) groups, a molecule or a macromolecule containing at least three reactive amine functionalities where a primary amine (—NH 2 ) contributes two to the total number of reactive functionalities while a secondary amine (—NHR—, where R can be any aliphatic or aromatic organic fragment) contributes one to the total number of reactive functionalities; and a molecule or a macromolecule where the total number of reactive functionalities arising from any combination of isocyanate (—N═C═O), alcohol (—OH), primary amine (—NH 2 ) and secondary amine (—NHR—, where R can be any aliphatic or aromatic organic fragment) adds up to at least three, 1,4-divinyloxybutane, divinylsulfone, diallyl phthalate, diallyl acrylamide, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate or mixtures thereof. 
       
     
     
         4 . The method of  claim 1 , wherein said polymer precursor mixture comprises a non-crosslinking monomer selected from the group consisting of: Styrenic monomers, styrene, methylstyrene, ethylstyrene (ethylvinylbenzene), chlorostyrene, chloromethylstyrene, styrenesulfonic acid, t-butoxystyrene, t-butylstyrene, pentylstyrene, alpha-methylstyrene, alpha-methyl-p-pentylstyrene; acrylic and methacrylic monomers, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, lauryl methacrylate, glycidyl acrylate, glycidyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, diethylene glycol acrylate, diethylene glycol methacrylate, glycerol monoacrylate, glycerol monomethacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, butanediol monoacrylate, butanediol monomethacrylate; unsaturated carboxylic acid monomers, acrylic acid, methacrylic acid; alkyl vinyl ether monomers, methyl vinyl ether, ethyl vinyl ether; vinyl ester monomers, vinyl acetate, vinyl propionate, vinyl butyrate; N-alkyl substituted acrylamides and methacrylamides, N-methylacrylamide, N-methylmethacrylamide, N-ethyl acrylamide, N-ethyl methacrylamide; nitrile monomers, acrylonitrile, methacrylonitrile; olefinic monomers, ethylene (H 2 C═CH 2 ) and the alpha-olefins (H 2 C═CHR) where R is any saturated hydrocarbon fragment; vinylic alcohols, vinyl alcohol; vinyl halides, vinyl chloride; vinylidene halides, vinylidene chloride, or mixtures thereof. 
     
     
         5 . The method of  claim 1 , wherein said thermoset polymer matrix comprises a styrene-divinylbenzene copolymer or a styrene-ethylvinylbenzene-divinylbenzene terpolymer. 
     
     
         6 . The method of  claim 1 , wherein said precursor mixture comprises divinylbenzene in an amount ranging from 3% to 35% by weight of the mixture of monomer, oligomer, or combinations thereof that react to form the matrix polymer. 
     
     
         7 . The method of  claim 1 , wherein said nano filler is selected from the group of nanofillers consisting of carbon black, fumed silica, fumed alumina, carbon nanotubes, carbon nanofibers, cellulosic nano fibers, natural clays, synthetic clays, fly ash, polyhedral oligomeric silsesquioxanes, metal clusters, metal alloy clusters, metal oxide clusters, or mixtures thereof. 
     
     
         8 . The method of  claim 1 , wherein said nano filler comprises carbon black, possessing a length that is less than 0.5 microns in at least one principal axis direction and an amount from 0.1% to 15% of said particle by volume. 
     
     
         9 . The method of  claim 1 , wherein said impact modifier has one or more reactive functionalities capable of causing said impact modifier to become grafted onto said thermoset polymer matrix. 
     
     
         10 . The method of  claim 1 , wherein said impact modifier is present in an amount ranging from 3% to 35% by weight of the impact modifier, plus the monomer, oligomer, or combinations thereof that react to form the matrix polymer. 
     
     
         11 . The method of  claim 1 , wherein said impact modifier comprises at least one of a monomer, an oligomer or a polymer having one or more reactive functionalities; obtained or derived from a petrochemical feedstock, a renewable feedstock, or a combination thereof. 
     
     
         12 . The method of  claim 1 , wherein said impact modifier comprises at least one of a monomer, oligomer or polymer, having one or more reactive functionalities; selected from the group consisting of: Polybutadiene (including its solid and liquid forms, and any of its variants comprising different cis-1,4, trans-1,4, and vinyl-1,2 isomer contents), natural rubber, synthetic polyisoprene, polychloroprene, nitrile rubbers, other diene rubbers, partially or completely hydrogenated versions of any of the diene rubbers, acrylic rubbers, olefinic rubbers, epichlorohydrin rubbers, fluorocarbon rubbers, fluorosilicon rubbers, block and/or graft copolymers prepared from formulations comprising styrenic monomers and diene monomers, partially or completely hydrogenated versions of block and/or graft copolymers prepared from formulations comprising styrenic monomers and diene monomers, silicone rubbers, rubbers containing aliphatic or partially aromatic polyether chain segments, rubbers containing aliphatic or partially aromatic polyester chain segments, rubbers containing aliphatic or partially aromatic polyurethane chain segments, rubbers containing aliphatic or partially aromatic polyurea chain segments, rubbers containing aliphatic or partially aromatic polyamide chain segments, ionomer resins which may be partially or wholly be neutralized with counterions; other rubbery homopolymers, copolymers containing random, block, graft, star, or core-shell morphologies, and mixtures thereof; and the monomeric or oligomeric precursors of any of the cited types of rubbery polymers. 
     
     
         13 . The method of  claim 1 , wherein said impact modifier comprises at least one of a monomer, oligomer or polymer, having one or more reactive functionalities; obtained or derived from renewable resources selected from the group consisting of soybean, sunflower, canola, castor, olive, peanut, cashew nut, pumpkin seed, rapeseed, corn, rice, sesame, cottonseed, palm, coconut, safflower, linseed, hemp, castor bean, tall oil, fish oil, lard, neatsfoot oil, tallow oil and similar natural fats and oils. 
     
     
         14 . The method of  claim 1 , wherein said polymer precursor mixture further comprises additional formulation ingredients selected from the group of ingredients consisting of: Initiators, catalysts, inhibitors, dispersants, stabilizers, rheology modifiers, buffers, antioxidants, defoamers, plasticizers, pigments, flame retardants, smoke retardants, or mixtures thereof. 
     
     
         15 . The method of  claim 1 , wherein said suspension polymerizing comprises rapid rate polymerizing. 
     
     
         16 . The method of  claim 1 , wherein said heat treatment is performed in a medium including a vacuum, a non-oxidizing gas, a mixture of non-oxidizing gases, a liquid, or a mixture of liquids; or in a downhole environment of a hydrocarbon reservoir. 
     
     
         17 . The method of  claim 1 , wherein said particle is a bead having an average roundness of at least 0.7 and an average sphericity of at least 0.7 as measured by the use of a Krumbien/Sloss chart. 
     
     
         18 . The method of  claim 1 , wherein said particle has an average diameter that ranges from 0.1 mm to 4 mm. 
     
     
         19 . The method of  claim 1 , wherein said packed mass or said partial monolayer exhibits a static conductivity of at least 100 mDft after 200 hours at a temperature greater than 80° F.