High performance proppants

Abstract

Embodiments disclosed herein provide coated particles that can be used, for example, in the extraction of oil and gas from subterranean formations.

1 . A coated particle comprising:
 a particle; and   a coating comprising at least one phenol-aldehyde resin layer and at least one polyurethane layer.   
     
     
         2 . The coated particle of  claim 1 , wherein the particle the at least one polyurethane layer is an outer layer. 
     
     
         3 . The coated particle of  claim 1 , wherein the polyurethane layer encapsulates the phenol-aldehyde resin layer. 
     
     
         4 . The coated particle of  claim 1 , wherein the particle is sand, silica, rocks, minerals, ceramic, bauxite, polymeric particles, or any combination thereof. 
     
     
         5 - 16 . (canceled) 
     
     
         17 . The coated particle of  claim 1 , wherein the coated particle comprises the phenol-aldehyde resin in an amount of about 0.5% to about 6.0% wt/wt. 
     
     
         18 . The coated particle of  claim 1 , wherein the coated particle comprises the polyurethane in an amount of about 0.25% to about 2.00% wt/wt solids 
     
     
         19 - 21 . (canceled) 
     
     
         22 . The coated particle of  claim 1 , wherein the coated particle comprises less than or equal to about 5% wt fillers. 
     
     
         23 - 24 . (canceled) 
     
     
         25 . A coated particle comprising:
 a particle;   and a coating comprising at least one phenol-aldehyde resin layer and at least one epoxy emulsion layer and/or a layer comprising a mixture of phenol-aldehyde resin and epoxy emulsion.   
     
     
         26 . The coated particle of  claim 25 , wherein the at least one epoxy emulsion layer is the outer layer. 
     
     
         27 . The coated particle of  claim 25 , wherein the particle is sand, silica, rock, mineral, ceramic, bauxite, polymeric particle, or any combination thereof. 
     
     
         28 - 38 . (canceled) 
     
     
         39 . The coated particle of  claim 25 , wherein the coated particle comprises a first phenol-aldehyde resin layer, a second phenol-aldehyde resin layer, a first epoxy emulsion layer, and a second epoxy emulsion layer, wherein:
 the first epoxy emulsion layer encapsulates the first phenol-aldehyde resin layer;   the second phenol-aldehyde resin layer encapsulates the first epoxy emulsion layer, and   the second epoxy emulsion layer encapsulates the second phenol-aldehyde resin layer.   
     
     
         40 - 44 . (canceled) 
     
     
         45 . The coated particle of  claim 25 , wherein the coated particle comprises the phenol-aldehyde resin in an amount of about 0.5% to about 6.0% wt/wt. 
     
     
         46 . The coated particle of  claim 25 , wherein the coated particle comprises the epoxy resin in an amount of about 0.25% to about 2.00% wt/wt solids 
     
     
         47 - 52 . (canceled) 
     
     
         53 . A coated particle comprising a particle, a first layer, a second layer, a third layer, and a fourth layer, wherein:
 the first layer encapsulates the particle,   the second layer encapsulates the first layer,   the third layer encapsulates the second layer, and   the fourth layer encapsulates the third layer,   wherein the first layer is a phenol-aldehyde resin layer, the second layer is a phenol-aldehyde resin layer, the third layer is a phenol-aldehyde resin layer, and the fourth layer is an epoxy emulsion layer or a polyurethane layer.   
     
     
         54 . The coated particle of  claim 53 , wherein the first, second, or third layer are each independently a phenol-aldehyde/epoxy resin layer. 
     
     
         55 - 61 . (canceled) 
     
     
         62 . A process for preparing a coated particle of  claim 25 , the process comprising:
 coating a particle with at least one phenol-aldehyde resin layer; and   coating the particle coated with the phenol-aldehyde resin layer with an epoxy emulsion layer.   
     
     
         63 . (canceled) 
     
     
         64 . The process of  claim 62 , further comprising curing the at least one phenol-aldehyde resin layer with a curative agent, wherein the curative agent is applied in an amount of about 5 to about 15 wt. % of the phenol-aldehyde resin. 
     
     
         65 . The process of  claim 64 , wherein the curative agent is hexamethylenetetramine, hexamine, paraformaldehyde, melamine resin, triphenylphosphine, or an oxazolidine. 
     
     
         66 . The process of  claim 62 , wherein the epoxy emulsion is contacted with the phenol-aldehyde resin coated particle in amount of about 0.25 to about 2.00% wt/wt solids. 
     
     
         67 . The process of  claim 62 , wherein the epoxy emulsion comprises a hardener. 
     
     
         68 . The process of  claim 67 , wherein the hardener is an aliphatic amine, a cycloaliphatic amine; an aromatic amine, an anhydride, or any combination thereof. 
     
     
         69 . The process of  claim 67 , wherein the hardener is diethylene triamine (DETA), triethylenetetraamine (TETA), tetraethylenepentamine (TEPA), aminoethylpiperazine (N-AEP), m-xylenediamine (MXDA), 2-methylpentanediamine (MPMD) isophoronediamine (IPDA), methylene-di(cyclohexylamine) (PACM), diaminocyclohexane, 4,4′ Diaminodiphenyl methane (DDM), 4,4′ Diaminodiphenyl sulfone (DDS), methylene-bis(diisopropylaniline) (MPDA), methylene-bis(dimethylaniline), diethyl toluene diamine (DETDA), hexahydrophthalic acid anhydride, dicyclopentadiene dianhydride, mellitic anhydride, methyl tetrahydrophthalic anhydride, or nadic methyl anhydride, or any combination thereof. 
     
     
         70 - 76 . (canceled)