WO2012104190A1 - Agent de soutènement - Google Patents

Agent de soutènement Download PDF

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Publication number
WO2012104190A1
WO2012104190A1 PCT/EP2012/051195 EP2012051195W WO2012104190A1 WO 2012104190 A1 WO2012104190 A1 WO 2012104190A1 EP 2012051195 W EP2012051195 W EP 2012051195W WO 2012104190 A1 WO2012104190 A1 WO 2012104190A1
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WO
WIPO (PCT)
Prior art keywords
isocyanate
particle
proppant
coating
polycarbodiimide coating
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Application number
PCT/EP2012/051195
Other languages
English (en)
Inventor
Christopher M. Tanguay
Rajesh Kumar
Original Assignee
Basf Se
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Publication date
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Publication of WO2012104190A1 publication Critical patent/WO2012104190A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/60—Compositions for stimulating production by acting on the underground formation
    • C09K8/80—Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open
    • C09K8/805—Coated proppants
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/60—Compositions for stimulating production by acting on the underground formation
    • C09K8/62—Compositions for forming crevices or fractures

Definitions

  • the subject invention generally relates to a proppant and a method of forming the proppant. More specifically, the subject invention relates to a proppant which comprises a particle and a coating disposed on the particle, and which is used during hydraulic fracturing of a subterranean formation.
  • Petroleum fuels are typically procured from subsurface reservoirs via a wellbore. Petroleum fuels are currently procured from low-permeability reservoirs through hydraulic fracturing of subterranean formations, such as bodies of rock having varying degrees of porosity and permeability. Hydraulic fracturing enhances production by creating fractures that emanate from the subsurface reservoir or wellbore, and provides increased flow channels for petroleum fuels.
  • Hydraulic fracturing enhances production by creating fractures that emanate from the subsurface reservoir or wellbore, and provides increased flow channels for petroleum fuels.
  • specially- engineered carrier fluids are pumped at high pressure and velocity into the subsurface reservoir to cause fractures in the subterranean formations.
  • a propping agent i.e., a proppant, is mixed with the carrier fluids to keep the fractures open when hydraulic fracturing is complete.
  • the proppant typically comprises a particle and a coating disposed on the particle.
  • the proppant remains in place in the fractures once the high pressure is removed, and thereby props open the fractures to enhance petroleum fuel flow into the wellbore. Consequently, the proppant increases procurement of petroleum fuel by creating a high-permeability, supported channel through which the petroleum fuel can flow.
  • many existing proppants comprise coatings having inadequate crush resistance. That is, many existing proppants comprise non-uniform coatings that include defects, such as gaps or indentations, which contribute to premature breakdown and/or failure of the coating. Since the coating typically provides a cushioning effect for the proppant and evenly distributes high pressures around the proppant, premature breakdown and/or failure of the coating undermines the crush resistance of the proppant. Crushed proppants cannot effectively prop open fractures and often contribute to impurities in unrefined petroleum fuels in the form of dust particles.
  • low-viscosity carrier fluids having viscosities of less than about 3,000 cps at 80 °C.
  • Low-viscosity carrier fluids are typically pumped into wellbores at higher pressures than high-viscosity carrier fluids to ensure proper fracturing of the subterranean formation. Consequently, many existing coatings fail mechanically, i.e., shear off the particle, when exposed to high pressures or react chemically with low-viscosity carrier fluids and degrade.
  • a proppant for hydraulically fracturing a subterranean formation, a method of forming the proppant, and a method of hydraulically fracturing a subterranean formation are provided.
  • the proppant includes a particle and a polycarbodiimide coating disposed on the particle.
  • the polycarbodiimide coating comprises the reaction product of an isocyanate reacted in the presence of a trialkyl phosphate.
  • the method of forming the proppant includes the steps of providing the particle, the isocyanate, and the trialkyl phosphate.
  • the method of forming the proppant also includes the steps of reacting the isocyanate in the presence of the trialkyl phosphate to form the polycarbodiimide coating and coating the particle with the polycarbodiimide coating.
  • the present invention provides a proppant and a method of forming, or preparing, the proppant, a method of hydraulically fracturing a subterranean formation, and a method of filtering a fluid.
  • the proppant comprises a particle and a coating disposed on the particle.
  • the proppant is typically used, in conjunction with a carrier fluid, to hydraulically fracture a subterranean formation which defines a subsurface reservoir (e.g. a wellbore or reservoir itself).
  • the proppant props open the fractures in the subterranean formation after the hydraulic fracturing.
  • the proppant may also be used to filter unrefined petroleum fuels, e.g. crude oil, in fractures to improve feedstock quality for refineries.
  • the proppant can also have applications beyond hydraulic fracturing and crude oil filtration, including, but not limited to, water filtration and artificial turf.
  • the proppant comprises the particle and the coating disposed on the particle.
  • the particle typically has a particle size distribution of from about 10 to about 100 mesh, more typically from about 20 to about 70 mesh, as measured in accordance with standard sizing techniques using the United States Sieve Series. That is, the particle typically has a particle size of from about 149 to about 2,000, more typically of from about 210 to about 841, ⁇ . Particles having such particle sizes allow less coating to be used, allow the coating to be applied to the particle at a lower viscosity, and allow the coating to be disposed on the particle with increased uniformity and completeness as compared to particles having other particle sizes.
  • the shape of the particle is not critical; the particle can be any shape. Typically, the particle is either round or roughly spherical. Particles having a spherical shape typically impart a smaller increase in viscosity to a hydraulic fracturing composition than particles having other shapes.
  • the hydraulic fracturing composition is a mixture comprising the carrier fluid and the proppant.
  • the particle typically contains less than about 1 part by weight of moisture based on 100 parts by weight of the particle. Particles containing higher than about 1 part by weight of moisture typically interfere with sizing techniques and prevent uniform coating of the particle.
  • Suitable particles include any known particle for use during hydraulic fracturing, water filtration, or artificial turf preparation.
  • suitable particles include minerals, ceramics such as sintered ceramic particles, sands, nut shells (including crushed walnut hulls), gravels, mine tailings, coal ashes, rocks (including bauxite), smelter slag, diatomaceous earth, crushed charcoals, micas, clays (including kaolin clay particles), sawdust, wood chips, resinous particles (including phenol-formaldehyde particles), polymeric particles, and combinations thereof. It is to be appreciated that other particles not recited herein may also be suitable.
  • Sand is a preferred particle and when applied in this technology is commonly referred to as fracturing, or frac, sand.
  • suitable sands include, but are not limited to, Arizona sand, Wisconsin sand, Missouri sand, Brady sand, Northern White sand, and Ottawa sand. Based on cost and availability, inorganic materials such as sand and sintered ceramic particles are typically favored for applications not requiring filtration.
  • a specific example of a sand that is suitable as a particle is Arizona sand, which is a natural grain that is derived from weathering and erosion of pre-existing rocks. As such, this sand is typically coarse and is roughly spherical.
  • Another specific example of a sand that is suitable as a particle is Ottawa sand, commercially available from U.S. Silica Company of Berkeley Springs, WV.
  • Yet another specific example of a sand that is suitable as a particle is Wisconsin sand, commercially available from Badger Mining Corporation of Berlin, WI.
  • Particularly preferred sands are Ottawa and Wisconsin sands. Ottawa and Wisconsin sands of various sizes, such as 20/40, 30/50, 40/70, and 70/140 can be used.
  • suitable sintered ceramic particles include, but are not limited to, aluminum oxide, silica, bauxite, and combinations thereof.
  • the sintered ceramic particle may also include clay-like binders.
  • An active agent may also be included in the particle.
  • suitable active agents include, but are not limited to, organic compounds, microorganisms, and catalysts.
  • microorganisms include, but are not limited to, anaerobic microorganisms, aerobic microorganisms, and combinations thereof.
  • a suitable microorganism is commercially available from LUCA Technologies of Golden, Colorado.
  • suitable catalysts include fluid catalytic cracking catalysts, hydroprocessing catalysts, and combinations thereof.
  • Fluid catalytic cracking catalysts are typically selected for applications requiring petroleum gas and/or gasoline production from crude oil.
  • Hydroprocessing catalysts are typically selected for applications requiring gasoline and/or kerosene production from crude oil. It is also to be appreciated that other catalysts, organic or inorganic, not recited herein may also be suitable.
  • Such additional active agents are typically favored for applications requiring filtration.
  • sands and sintered ceramic particles are typically useful as a particle for support and propping open fractures in the subterranean formation which defines the subsurface reservoir, and, as an active agent, microorganisms and catalysts are typically useful for removing impurities from crude oil or water. Therefore, a combination of sands/sintered ceramic particles and microorganisms/catalysts as active agents are typical for crude oil or water filtration.
  • Suitable particles may even be formed from resins and polymers.
  • resins and polymers for the particle include, but are not limited to, polyurethanes, polycarbodiimides, polyureas, acrylics, polyvinylpyrrolidones, acrrylonitrile-butadiene styrenes, polystyrenes (including polyvinyl styrene), polyvinyl chlorides, fluoroplastics, polysulfides, nylon, polyamide imides, and combinations thereof.
  • the proppant also comprises the coating disposed on the particle.
  • the terminology “disposed on” encompasses the coating being “disposed about” the particle and also encompasses both partial and complete covering of the particle by the coating.
  • the coating is typically present in the proppant in an amount of from about 0.1 to about 10, more typically of from about 0.5 to about 7.5, and most typically of from about 1.0 to about 6.0, percent by weight based on 100 parts by weight of the particle. However, it should be appreciated that the coating can be present in the proppant in an amount of greater than about 10 percent by weight based on 100 parts by weight of the proppant.
  • the coating may be formed in-situ where the coating is disposed on the particle during formation of the coating. Said differently, the components of the coating are typically combined with the particle and the coating is disposed on the particle.
  • the coating is formed and some time later applied to, e.g. mixed with, the particle and exposed to temperatures exceeding about 100°C to coat the particle and form the proppant.
  • this embodiment allows the coating to be formed at a location designed to handle chemicals, under the control of personnel experienced in handling chemicals. Once formed, the coating can be transported to another location, applied to the particle, and heated.
  • Other advantages of this embodiment include quicker sand coating cycle times, less generation of volatile organic compounds during coating of the particle, and reduced use of raw materials.
  • the coating may be applied immediately following the manufacturing of the frac sand, when the frac sand is already at elevated temperature, eliminating the need to reheat the coating and the frac sand, thereby reducing the amount of energy required to form the proppant.
  • the proppant can comprise a particle having multiple identical or different coatings disposed on the particle.
  • the coating may include an additive component.
  • Suitable additive components include, but are not limited to, surfactants, blowing agents, blocking agents, curatives, dyes, pigments, diluents, solvents, specialized functional additives such as antioxidants, ultraviolet stabilizers, biocides, adhesion promoters, antistatic agents, fire retardants, fragrances, and combinations of the group.
  • a pigment allows the coating to be visually evaluated for thickness and integrity and can provide various marketing advantages.
  • the adhesion promoter is also commonly referred to in the art as a coupling agent or as a binder agent.
  • the adhesion promoter binds the coating to the particle. More specifically, the adhesion promoter typically has organofunctional silane groups to improve adhesion of the coating to the particle. Without being bound by theory, it is thought that the adhesion promoter allows for covalent bonding between the particle and the coating.
  • the adhesion promoter may be incorporated into the coating. As such, the particle is then simply exposed to the adhesion promoter when the coating is applied to the particle.
  • the surface of the particle is activated with the adhesion promoter by applying the adhesion promoter to the particle prior to coating the particle with the coating.
  • the adhesion promoter can be applied to the particle by a wide variety of application techniques including, but not limited to, spraying, dipping the particles in the coating, etc.
  • the adhesion promoter is useful for applications requiring excellent adhesion of the coating to the particle, for example, in applications where the proppant is subjected to shear forces in an aqueous environment.
  • Use of the adhesion promoter provides adhesion of the coating to the particle such that the coating will remain adhered to the surface of the particle even if the proppant, including the coating, the particle, or both, fractures due to closure stress.
  • adhesions promoters which are silicon-containing, include, b u t a r e n o t l i m i t e d t o , g 1 y c i d o x y p r o p y 1 1 r i m e t h o x y s i 1 a n e , aminoethylaminopropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, gamma- aminopropyltriethoxysilane, vinylbenzylaminoethylaminopropyltrimethoxysilane, glycidoxypropylmethy ldiethoxy s ilane, chloropropy ltrimethoxy s ilane, phenyltrimethoxysilane, vinyltriethoxysilane, t
  • adhesion promoters include, but are not limited to, SILQUESTTM A1100, SILQUESTTM Al l 10, SILQUESTTM A1120, SILQUESTTM 1130, SILQUESTTM Al l 70, SILQUESTTM A-189, and SILQUESTTM Y9669, all commercially available from Momentive Performance Materials of Albany, NY.
  • the silicon-containing wetting agent may be present in the proppant in an amount of from about 0.001 to about 10, typically from about 0.01 to about 7.5, and more typically from about 0.04 to about 5, percent by weight based on 100 parts by weight of the coating.
  • Suitable coatings include any known coating for use during hydraulic fracturing, water filtration, or artificial turf preparation.
  • the coating comprises a polymer which may include moieties selected from the group of isocyanate moieties, isocyanurate moieties, uretdione moieties, carbodiimide moieties, uretonimine moieties, and urethane moieties.
  • the coating is a polycarbodiimide coating.
  • the polycarbodiimide coating is typically selected for applications requiring excellent coating stability and adhesion to the particle.
  • the polycarbodiimide coating is particularly applicable when the proppant is exposed to significant compression and/or shear forces, and temperatures exceeding about 500°F in the subterranean formation and/or subsurface reservoir defined by the formation.
  • the polycarbodiimide coating is generally viscous to solid nature, and depending on molecular weight, is typically sparingly soluble or insoluble in organic solvents. Any suitable polycarbodiimide coating may be used.
  • the polycarbodiimide coating can be formed from all known raw materials, methods, and chemical reactions.
  • the polycarbodiimide coating is typically formed by reacting an isocyanate in the presence of a catalyst.
  • the polycarbodiimide coating may be the reaction product of more than two isocyanates.
  • the physical properties of the polycarbodiimide coating such as hardness, strength, toughness, creep, and brittleness can be further optimized and balanced.
  • the isocyanate may be any type of isocyanate known to those skilled in the art.
  • the isocyanate may be a polyisocyanate having two or more functional groups, e.g. two or more NCO functional groups. Suitable isocyanates include, but are not limited to, aliphatic and aromatic isocyanates.
  • the isocyanate is selected from the group of diphenylmethane diisocyanates (MDIs), polymeric diphenylmethane diisocyanates (pMDIs), toluene diisocyanates (TDIs), hexamethylene diisocyanates (HDIs), isophorone diisocyanates (IPDIs), and combinations thereof.
  • MDIs diphenylmethane diisocyanates
  • pMDIs polymeric diphenylmethane diisocyanates
  • TDIs toluene diisocyanates
  • HDIs hexamethylene diisocyanates
  • the isocyanate may be an isocyanate prepolymer.
  • the isocyanate prepolymer is typically a reaction product of an isocyanate and a polyol and/or a polyamine.
  • the isocyanate used in the prepolymer can be any isocyanate as described above.
  • the polyol used to form the prepolymer is typically selected from the group of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butane diol, glycerol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, biopolyols, and combinations thereof.
  • the polyamine used to form the prepolymer is typically selected from the group of ethylene diamine, toluene diamine, diaminodiphenylmethane and polymethylene polyphenylene polyamines, aminoalcohols, and combinations thereof.
  • suitable aminoalcohols include ethanolamine, diethanolamine, triethanolamine, and combinations thereof.
  • isocyanates that may be used to prepare the polycarbodiimide coating include, but are not limited to, toluylene diisocyanate; 4,4'-diphenylmethane diisocyanate; m-phenylene diisocyanate; 1,5 -naphthalene diisocyanate; 4-chloro-l ; 3- phenylene diisocyanate; tetramethylene diisocyanate; hexamethylene diisocyanate; 1,4- dicyclohexyl diisocyanate; 1 ,4-cyclohexyl diisocyanate, 2,4, 6-toluylene triisocyanate, 1 ,3-diisopropylphenylene-2,4-dissocyanate; 1 -methyl-3,5-diethylphenylene-2,4- diisocyanate; l ,3,5-triethylphenylene-2,4-diisocyanate; l,3,3,5-tri
  • suitable polycarbodiimide coatings can also be prepared from aromatic diisocyanates or isocyanates having one or two aryl, alkyl, arakyl or alkoxy substituents wherein at least one of these substituents has at least two carbon atoms.
  • suitable isocyanates include LUPRANATE ® L5120, LUPRANATE ® M, LUPRANATE ® ME, LUPRANATE ® MI, LUPRANATE ® M20, and LUPRANATE ® M70, all commercially available from BASF Corporation of Florham Park, NJ.
  • the one or more isocyanates are typically heated in the presence of the catalyst to form the polycarbodiimide coating.
  • One or more catalysts can be used to form the polycarbodiimide coating.
  • the catalyst may be any type of catalyst known to those skilled in the art. Generally, the catalyst is selected from the group of phosphorous compounds, tertiary amides, basic metal compounds, carboxylic acid metal salts, non- basic organo-metallic compounds, and combinations thereof.
  • the polycarbodiimide coating can also be formed from various catalysts disclosed in U.S. Patent No. 4,284,730 (the '730 patent), which is hereby incorporated by reference in its entirety.
  • the '730 patent discloses formation of carbodiimide by reacting the isocyanate and/or other raw materials in the presence of the catalyst.
  • Genuses of catalysts disclosed in the '730 patent include phosphates, phospholene oxides, diaza- and oxaza phospholenes and phosphorinanes, triaryl arsines, metallic derivatives of acetlyacetone, phosphate esters, metal complexes derived from a d-group transition element and a ⁇ bonding ligand, organotin compounds, organic and metal carbene complexes, and various titanium (IV), copper (I) and copper (II) complexes.
  • the genuses of catalysts disclosed in the '730 patent are discussed in detail immediately below.
  • the polycarbodiimide coating can be formed using catalysts comprising phosphorous, such as phosphates, phospholene oxides, diaza- and oxaza phospholenes and phosphorinanes.
  • catalysts comprising phosphorous include, but are not limited to, phosphate esters and other phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2- ethylhexyldiphenyl phosphate, and the like; acidic phosphates such as methyl acid phosphate, ethyl acid phosphate, isopropyl
  • the polycarbodiimide coating can also be formed using catalysts comprising phospholene 1 -oxides and 1 -sulfides.
  • Phospholene 1 -oxides and 1 -sulfides and methods for their preparation are described in U. S. Pat. Nos. : 2,663,737; 2,663,738; and 2,853,473, which are hereby incorporated by reference in their entirety.
  • phospholene 1 -oxides and 1 -sulfides include, but are not limited to 1 -phenyl- 2-phospholene-l -oxide; 3 -methyl-1 -phenyl-2-phospholene-l -oxide; 1 -phenyl-2- phospholene-1 -sulfide; 1 -ethyl-2-phospholene-l -oxide; 1 -ethyl-3 -methyl -2 -phospholene- 1-oxide; l-ethyl-3-methyl-2-phospholene-l-sulfide; and the isomeric phospholanes corresponding to the above-named compounds.
  • the catalyst can comprise polymer bound phospholene oxides such as those disclosed in U.S. Patent Nos. 4, 105,643 and 4,105,642, which are hereby incorporated by reference in their entirety.
  • the polycarbodiimide coating can also be formed using catalysts comprising diaza and oxaza phospholenes and phosphorinanes. Diaza and oxaza phospholenes and phosphorinanes and methods for their preparation are described in U.S. Pat. No. 3,522,303, which is hereby incorporated by reference in its entirety.
  • diaza- and oxaza phospholenes and phosphorinanes include, but are not limited to, 2-ethyl-l,3- dimethyl-l,3,2-diazaphospholane-2-oxide; 2-chloromethyl-l, 3 -dimethyl-1, 3,2- diazaphospholane-2-oxide; 2-trichloromethyl-l,3-dimethyl-l,3,2-diazaphospholane-2- oxide; 2-phenyl- 1 ,3 -dimethyl- 1 ,3 ,2-diazaphospholane-2-ox i d e ; 2 -phenyl- 1 ,3 -dimethyl- 1 ,3 ,2-diaza-phosphorinane-2 -oxide; 2-benzyl- 1 ,3 -dimethyl-1 ,3 ,2-diazaphospholane-2- oxide; 2-allyl-l,3-dimethyl-l,3,2-diazaphospholane-2-oxide; 2-bromomethyl- 1,3- dimethyl
  • the polycarbodiimide coating can also be formed using catalysts comprising triaryl arsine.
  • Triaryl arsines and methods for their preparation are described in U.S. Pat. No.3,406,198, which is hereby incorporated by reference in its entirety.
  • triaryl arsines include, but are not limited to, triphenylarsine, tris(p- tolyl)arsine, tris(p-methoxyphenyl)arsine, tris(p-ethoxyphenyl)arsine, tris(p- chlorophenyl) arsine, tris(p-fluorophenyl)arsine, tris(2,5-xylyl)arsine, tris(p- cyanophenyl)arsine, tris(l-naphthyl)arsine, tris(p-methylmercaptophenyl)arsine, tris(p- biphenylyl)arsine, p-chlorophenyl bis(ptolyl)arsine, phenyl(p-chlorophenyl)(p- bromophenyl)arsine, and the like.
  • catalysts comprising arsine compounds described in U.S. Patent No. 4,143,063, which is hereby incorporated by reference in its entirety, can be used to form the polycarbodiimide coating.
  • arsine compounds include, but are not limited to, triphenylarsine oxide, triethylarsine oxide, polymer bound arsine oxide, and the like.
  • the polycarbodiimide coating can also be formed using catalysts comprising metallic derivatives of acetlyacetone.
  • Metallic derivatives of acetlyacetone and methods are described in U.S. Pat. No. 3,152,131, which is hereby incorporated by reference in its entirety.
  • Specific examples of metallic derivatives of acetlyacetone include, but are not limited to, metallic derivatives of acetylacetone such as the beryllium, aluminum, zirconium, chromium, and iron derivatives.
  • the polycarbodiimide coating can be formed using catalysts comprising metal complexes derived from a d-group transition element and ⁇ -bonding ligand selected from the group consisting of carbon monoxide, nitric oxide, hydrocarbylisocyanides, trihydrocarbylphosphine, trihydrocarbylarsine , tr ihy dro carby l sti l b i ne , an d dihydrocarbylsulfide wherein hydrocarbyl in each instance contains from 1 to 12 carbon atoms, inclusive, provided that at least one of the ⁇ -bonding ligands in the complex is carbon monoxide or hydrocarbylisocyanide.
  • ⁇ -bonding ligand selected from the group consisting of carbon monoxide, nitric oxide, hydrocarbylisocyanides, trihydrocarbylphosphine, trihydrocarbylarsine , tr ihy dr
  • metal complexes include, but are not limited to, iron pentacarbonyl, di-iron pentacarbonyl, tungsten hexacarbonyl, molybdenum hexacarbonyl, chromium hexacarbonyl, dimanganese decacarbonyl, nickel t e tr a c ar b o ny 1 , ruthenium pentacarbony 1, the complex of iron tetracarbonyl:methylisocyanide, and the like.
  • the polycarbodiimide coating can be formed using catalysts comprising organotin compounds.
  • organotin compounds include, but are not limited to, dibutytin dilaurate, dibutyltin diacetate, dibutyltin di(2-ethylhexanoate), dioctyltin dilaurate, dibutylin maleate, di(n-octyl)tin maleate, bis(dibutylacetoxytin) oxide, bis(dibutyllauroyloxytin) oxide, dibutyltin dibutoxide, dibutyltin dimethoxide, dibutyltin disalicilate, dibutyltin bis(isooctylmaleate), dibutyltin bis(isopropylmaleate), dibutyltin oxide, tributyltin acetate, tributyltin isopropyl succinate, tributy
  • Typical organotin compounds include, but are not limited to, stannous oxalate, stannous oleate and stannous 2-ethylhexanoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dilaurylmercaptide, dibutyltin bis(isooctylmercaptoacetate), dibutyltin oxide, bis(triphenyltin) oxide, and bis(tri-n-butyltin) oxide.
  • Various catalysts comprising organic and metal carbene complexes can also be used to form the polycarbodiimide coating.
  • various catalysts comprising titanium(IV) complexes, copper(I) and copper(II) complexes can also be used to form the polycarbodiimide coating via living carbodiimide polymerizations.
  • the polycarbodiimide coating can be formed via catalytic conversion of isocyanates to carbodiimides by cyclopentadienyl manganese tricarbonyl and cyclopentadienyl iron dicarbonyl dimer and derivatives.
  • Specific polycarbodiimide coatings include, but are not limited to, monomers, oligomers, and polymers of diisopropylcarbodiimide, dicyclohexylcabodiimide, methyl- tert-butylcarbodiimide, 2,6-diethylphenyl carbodiimide; di-ortho-tolyl-carbodimide; 2,2'- dimethyl diphenyl carbodiimide; 2,2'-diisopropyl-diphenyl carbodiimide; 2-dodecyl-2'-n- propyl-diphenylcarbodiimide; 2,2'-diethoxy-diphenyl dichloro-diphenylcarbodiimide; 2,2'-ditolyl-diphenyl carbodiimide; 2,2'-dibenzyl-diphenyl carbodiimide; 2,2'-dinitro- diphenyl carbodiimide; 2-e
  • the polycarbodiimide coating can be formed by reacting the isocyanate in the presence of the catalyst.
  • the polycarbodiimide coating can be the reaction product of one type of isocyanate. However, the polycarbodiimide coating is typically the reaction product of at least two different isocyanates.
  • the polycarbodiimide coating can also be formed from various chemical reactions disclosed in "Chemistry and Technology of Carbodiimides", John Wiley & Sons, Ltd., Chichester, West Wales, England (2007), which is hereby incorporated by reference in its entirety. As a specific example, the polycarbodiimide coating can be formed from:
  • Isocyanates isothiocyanates, for example:
  • P is N, P, As, Sb, or Bi; E is O or S; and R is alkyl or aryl halide
  • Nitrene rearrangements for example:
  • Haloformamidines or carbonimidoyl dihalides for example:
  • the proppant of the present invention comprises the particle and the polycarbodiiminde coating disposed on the particle.
  • the polycarbodiimide coating is the reaction product of the isocyanate reacted in the presence of a trialkyl phosphate.
  • the trialkyl phosphate is triethyl phosphate (TEP).
  • TEP triethyl phosphate
  • the trialkyl phosphate is typically mixed with the isocyanate in an amount of from about 0.1 to about 25, more typically from about 1 to about 20, and most typically from about 3 to about 15, percent by weight based on 100 parts by weight of the isocyanate.
  • the polycarbodiimide coating can also be the reaction product of the isocyanate reacted in the presence of the trialkyl phosphate and a phospholene oxide.
  • Suitable non limiting examples of the phospholene oxide include, but are not limited to, 3 -methyl- 1- phenyl-2-phospholene oxide (MPPO), l -phenyl-2-phospholen-l-oxide, 3-methyl-l -2- phospholen-l-oxi d e , 1 -ethy 1 -2-phospholen-l-ox i d e , 3 -methyl-l-pheny 1 -2-phospholen-l- oxide, 3-phospholene isomers thereof, and 3-methyl-l-ethyl-2-phospholene oxide (MEPO).
  • MPO 3-methyl-l-ethyl-2-phospholene oxide
  • the polycarbodiimide coating is the reaction product of the isocyanate reacted in the presence of TEP and MPPO. In another embodiment, the polycarbodiimide coating is the reaction product of the isocyanate reacted in the presence of TEP and MEPO.
  • the polycarbodiimide coating is the reaction product of the isocyanate reacted in the presence of the trialkyl phosphate and the phospholene oxide
  • the trialkyl phosphate and the phospholene oxide are typically collectively mixed with the isocyanate in an amount of less than about 25, more typically in an amount of from about 0.1 to about 25, more typically from about 0.2 to about 20, and most typically from about 0.3 to about 10, percent by weight based on 100 parts by weight of the isocyanate.
  • the percent by weight of the collective amount of the trialkyl phosphate and the phospholene oxide can include various ratios of the trialkyl phosphate and the phospholene oxide.
  • the polycarbodiimide coating is typically formed by heating the isocyanate in the presence of a trialkyl phosphate.
  • the polycarbodiimide coating can be formed at any temperature. Typically, formation of the polycarbodiimide coating occurs at a temperature greater than about 25, more typically at a temperature of from about 50 to about 250, and most typically from about 60 to about 230, °C.
  • the polycarbodiimide coating can also be formed from a modified isocyanate component.
  • the modified isocyanate component can be formed by heating the isocyanate in the presence of a trialkyl phosphate.
  • the modified isocyanate component can be formed and the polycarbodiimide coating can formed immediately therefrom or the modified component can be formed and the polycarbodiimide coating can be formed some time later therefrom.
  • the modified isocyanate component can be used in all applicable reactions and references cited in this disclosure to form the polycarbodiimide coating.
  • U.S. Patent No. 3,384,653 (the '653 patent), which is hereby incorporated by reference in its entirety, discloses formation of the modified isocyanate component by heating the isocyanate in the presence of the trialkyl phosphate.
  • the modified isocyanate component is formed by heating the isocyanate, such as methylenebis (phenyl isocyanate), in the presence of a trialkyl phosphate such as, triethyl phosphate (TEP).
  • TEP triethyl phosphate
  • the trialkyl phosphate catalyzes the chemical reaction of the isocyanate and subsequent formation of carbodiimide moieties and polycarbodiimide.
  • the modified isocyanate component comprises various isocyanate and carbodiimide moieties.
  • the isocyanate moieties react with the carbodiimide moieties to form uretonimine moieties.
  • the modified isocyanate component comprises the isocyanate moieties, the carbodiimide moieties, and the uretonimine moieties.
  • the modified isocyanate component is chemically stable and exhibits excellent shelf-life. Once the modified isocyanate component is formed, the polycarbodiimide coating can be formed therefrom and disposed about the particle to form the proppant.
  • the modified isocyanate component is merely a reaction intermediate.
  • the polycarbodiimide coating can be formed simply by heating the isocyanate in the presence of the TEP as necessary to react the isocyanate and form the polycarbodiimide coating.
  • the modified isocyanate component is not present as a discrete and independent component.
  • the modified isocyanate component is formed by mixing and heating the isocyanate, TEP, and optionally a catalyst and/or other additives.
  • One or more isocyanates can be mixed with TEP to form the modified isocyanate component.
  • the first isocyanate is further defined as a polymeric isocyanate
  • the second isocyanate is further defined as a monomeric isocyanate.
  • a mixture of LUPRANATE ® M20 and LUPRANATE ® M may be reacted to form the polycarbodiimide coating.
  • LUPRANATE ® M20 comprises polymeric isocyanates, such as polymeric diphenyl methane diisocyanate, and also comprises monomeric isocyanates.
  • LUPRANATE ® M comprises only monomeric isocyanates.
  • a monomeric isocyanate includes, but is not limited to, 2,4'-diphenylmethane diisocyanate (2,4'-MD I ) a n d 4 , 4 '-diphenylmethane diisocyanate (4,4'-MDI).
  • polymeric isocyanate includes isocyanates with two or more aromatic rings.
  • LUPRANATE ® M20 has an NCO content of about 31.5 weight percent and LUPRANATE ® M has an NCO content of about 33.5 weight percent.
  • Increasing an amount of LUPRANATE ® M20 in the mixture increases the amount of polymeric MDI in the mixture, and increasing the amount of polymeric MDI in the mixture affects the physical properties of the polycarbodiimide coating.
  • a mixture of LUPRANATE ® M20 and LUPRANATE® M is reacted to form the polycarbodiimide coating.
  • increasing an amount of LUPRANATE ® M20 and decreasing an amount of LUPRANATE ® M in the mixture forms a polycarbodiimide coating which is harder, stronger, and does not creep significantly; however, the polycarbodiimide coating may also be brittle.
  • LUPRANATE ® M20 can be mixed with TEP and the resulting mixture can be heated to form the modified isocyanate component.
  • a mixture of LUPRANATE ® M20 and LUPRANATE ® M can mixed with TEP and the resulting mixture can be heated to form the modified isocyanate component.
  • the TEP is typically mixed with the isocyanate in an amount of from about 0.1 to about 25, more typically from about 1 to about 20, and most typically from about 3 to about 15, percent by weight based on 100 parts by weight of the isocyanate to form the polycarbodiimide coating.
  • TEP can be mixed with the isocyanate in an amount of greater than about 25 percent by weight based on 100 parts by weight of the isocyanate.
  • the present invention also provides the method of forming, or preparing, the proppant.
  • the particle, the isocyanate, and the trialkyl phosphate are provided, the isocyanate is reacted in the presence of the trialkyl phosphate to form the polycarbodiimide coating, and the particle is coated with the polycarbodiimide coating.
  • the step of coating the particle with the polycarbodiimide coating is described additionally below.
  • the isocyanate is reacted in the presence of the trialkyl phosphate, such as TEP, to form the polycarbodiimide coating.
  • the isocyanate and the trialkyl phosphate are just as described above with respect to the polycarbodiimide coating. Reacting the isocyanate forms the polycarbodiimide coating.
  • the isocyanate may be reacted to form the polycarbodiimide coating simultaneous with the actual coating of the particle; alternatively, the isocyanate may be reacted to form the polycarbodiimide coating prior to the actual coating of the particle.
  • the isocyanate can be partially reacted to from the modified isocyanate component, whi ch can b e further heated to form the polycarbodiimide coating; alternatively, the isocyanate can be completely reacted to form the polycarbodiimide coating in a single step.
  • the method optionally includes the step of heating the particle to a temperature greater than about 150°C prior to or simultaneous with the step of coating the particle with the polycarbodiimide coating. If heated, the particle is typically heated to a temperature of from about 150 to about 250, more typically from about 180 to about 220, and most typically from about 190 to about 210, °C.
  • the method also optionally includes the step of heating the isocyanate in the presence of the trialkyl phosphate to a temperature of greater than about 150°C to from the polycarbodiimide coating.
  • the amount of time and temperature required to form the polycarbodiimide coating varies.
  • the isocyanate component is typically heated in the presence of the trialkyl phosphate to a temperature of greater than about 25, more typically greater than about 150, and most typically greater than about 180, °C to form the polycarbodiimide coating.
  • the isocyanate component is heated to a temperature of from about 190 to about 230, °C.
  • Various techniques can be used to coat the particle with the polycarbodiimide coating. These techniques include, but are not limited to, mixing, pan coating, fluidized- bed coating, co-extrusion, spraying, in-situ formation of the polycarbodiimide coating, and spinning disk encapsulation.
  • the technique for applying the coating to the particle is selected according to cost, production efficiencies, and batch size.
  • the amount of time and temperature required to form the polycarbodiimide coating i.e., the amount of time and temperature required to convert the isocyanate component into the polycarbodiimide coating, varies. Typically, the higher the temperature at which the proppant is heated, the less time required to form the polycarbodiimide coating.
  • the step of reacting the isocyanate in the presence of the trialkyl phosphate to form the polycarbodiimide coating and the step of coating the particle with the polycarbodiimide coating are collectively conducted in about 60 minutes or less, typically in about 30 minutes or less, more typically in about 15 minutes or less, and even more typically in about 3 to about 5 minutes.
  • the proppant can be further heated, i.e., post cured, to further crosslink the polycarbodiimide coating. Generally, further heating of the proppant will improve the performance of the proppant.
  • the step of reacting the isocyanate to form the polycarbodiimide coating, the step of coating the particle with the polycarbodiimide coating, and of the step of heating the proppant to further crosslink the polycarbodiimide coating are typically collectively conducted in about 60 minutes or less, more typically in about 30 minutes or less, and most typically in about 5 minutes or less.
  • the isocyanate is mixed with TEP and heated to a temperature of greater than about 200°C for up to about 60 minutes to form the modified isocyanate component with carbodiimide and/or uretonimine moieties.
  • the modified isocyanate component is mixed with the catalyst, such as 3 -methyl- 1 -phenyl-2-phospholene oxide, to form a reaction mixture.
  • the reaction mixture and the particle, comprising Ottawa sand, are added to a reaction vessel and agitated at a temperature of about 170°C for about 1 to about 5 minutes. During agitation at these conditions, the modified isocyanate component polymerizes to form the polycarbodiimide coating on the particle, i.e., the proppant.
  • the polycarbodiimide coating is formed in-situ, i.e., the polycarbodiimide coating is disposed on the particle simultaneous to the formation of the polycarbodiimide coating.
  • the proppant i.e., the particle having the polycarbodiimide coating formed thereon, can be heated (post-cured) at various temperatures and for various times to further cure the polycarbodiimide coating.
  • the particle comprising Ottawa sand is activated with the adhesion promoter, gamma-aminopropyltriethoxysilane.
  • the particle, now activated with gamma-aminopropyltriethoxysilane, is pre-heated to a temperature of greater than about 200°C and added to a reaction vessel.
  • the isocyanate is mixed with TEP to form the modified isocyanate component.
  • the modified isocyanate component is added to the reaction vessel, which contains the particle, i.e., Ottawa sand activated with the gamma- aminopropyltriethoxysilane and pre-heated, to form a reaction mixture.
  • the reaction mixture is heated to a temperature of from about 215 to about 230, °C and agitated for about 2 minutes.
  • the modified isocyanate component polymerizes to form the polycarbodiimide coating on the particle and thus form the proppant.
  • a silicone lubricant is sprayed on the proppant to further ensure that the proppant does not agglomerate.
  • the proppant i.e., the particle having the polycarbodiimide coating formed thereon, can be heated (post-cured) at a temperature of about 125°C for about 10 minutes to further cure the polycarbodiimide coating.
  • the proppant i.e., the particle having the polycarbodiimide coating formed thereon
  • the polycarbodiimide coating will further cure if it is exposed to elevated temperatures in the subterranean formation.
  • the isocyanate, TEP, and optionally a catalyst, such as 3 -methyl- 1 -phenyl-2-phospholene oxide are added to a reaction vessel, mixed, and heated to a temperature of about 190°C for about 60 minutes to form the modified isocyanate component.
  • the modified isocyanate component in a molten state, is cooled to a solidified, thermoplastic-like, crystalline state and is powderized.
  • the modified isocyanate component later applied to, e.g. mixed with, the particle and exposed to temperatures exceeding about 100°C to form the polycarbodiimide coating on the particle, i.e., to form the proppant.
  • the polycarbodiimide coating is disposed on the particle via mixing in a vessel, e.g. a reactor.
  • a vessel e.g. a reactor.
  • the individual components of the polycarbodiimide coating e.g. the isocyanate, the trialkyl phosphate, the particle, and optionally the catalyst, are added to the vessel to form a reaction mixture.
  • the components may be added in equal or unequal weight ratios.
  • the reaction mixture is typically agitated at an agitator speed commensurate with the viscosities of the components. Further, the reaction mixture is typically heated at a temperature commensurate with the polycarbodiimide coating technology and batch size.
  • the components of the polycarbodiimide coating are typically heated from a temperature of about 190°C to a temperature of about 230°C in about 10 minutes or less, depending on batch size. It is to be appreciated that the technique of mixing may include adding components to the vessel sequentially or concurrently. Also, the components may be added to the vessel at various time intervals and/or temperatures.
  • the polycarbodiimide coating is disposed on the particle via spraying. In particular, individual components of the polycarbodiimide coating are contacted in a spray device to form a coating mixture. The coating mixture is then sprayed onto the particle to form the proppant.
  • Spraying the coating mixture onto the particle can result in a uniform, complete, and defect-free polycarbodiimide coating disposed on the particle. Spraying the coating mixture can also result in a thinner and more consistent polycarbodiimide coating disposed on the particle as compared to other techniques, and thus the proppant is coated economically. Spraying the particle even permits a continuous manufacturing process. Spray temperature is typically selected by one known in the art according to coating technology and ambient humidity conditions.
  • the polycarbodiimide coating is disposed on the particle in-situ, i.e., in a reaction mixture comprising the components of the polycarbodiimide coating and the particle.
  • the polycarbodiimide coating is formed or partially formed as the polycarbodiimide coating is disposed on the particle.
  • In-situ polycarbodiimide coating formation steps typically include providing each component of the polycarbodiimide coating, providing the particle, combining the components of the polycarbodiimide coating and the particle, and disposing the polycarbodiimide coating on the particle. In-situ formation of the polycarbodiimide coating typically allows for reduced production costs by way of fewer processing steps as compared to existing methods for forming a proppant.
  • the formed proppant is typically prepared according to the method as set forth above and stored in an offsite location before being pumped into the subterranean formation and the subsurface reservoir. As such, spraying typically occurs offsite from the subterranean formation and subsurface reservoir. However, it is to be appreciated that the proppant may also be prepared just prior to being pumped into the subterranean formation and the subsurface reservoir. In this scenario, the proppant may be prepared with a portable coating apparatus at an onsite location of the subterranean formation and subsurface reservoir.
  • the proppant is useful for hydraulic fracturing of the subterranean formation to enhance recovery of petroleum and the like.
  • a hydraulic fracturing composition i.e., a mixture, comprising the carrier fluid, the proppant, and optionally various other components.
  • the carrier fluid is selected according to wellbore conditions and is mixed with the proppant to form the mixture which is the hydraulic fracturing composition.
  • the carrier fluid can be a wide variety of fluids including, but not limited to, kerosene and water. Typically, the carrier fluid is water.
  • Various other components which can be added to the mixture include, but are not limited to, guar, polysaccharides, and other components know to those skilled in the art.
  • the mixture is pumped into the subsurface reservoir, which may be the wellbore, to cause the subterranean formation to fracture. More specifically, hydraulic pressure is applied to introduce the hydraulic fracturing composition under pressure into the subsurface reservoir to create or enlarge fractures in the subterranean formation. When the hydraulic pressure is released, the proppant holds the fractures open, thereby enhancing the ability of the fractures to extract petroleum fuels or other subsurface fluids from the subsurface reservoir to the wellbore.
  • a method of hydraulically fracturing a subterranean formation which defines a subsurface reservoir with a mixture comprising a carrier fluid and the proppant, the proppant comprising the particle and the polycarbodiimide coating disposed on the particle comprises the step of pumping the mixture into the subsurface reservoir to cause the subterranean formation to fracture, wherein the polycarbodiimide coating comprises the reaction product of the isocyanate reacted in the presence of the trialkyl phosphate.
  • the proppant typically exhibits excellent thermal stability for high temperature and pressure applications, e.g. temperatures greater than about 100°C, typically greater than about 200°C, more typically greater than about 300°C, and even more typically greater than about 400°C, and/or pressures (independent of the temperatures described above) greater than about 7,500 psi, typically greater than about 10,000 psi, more typically greater than about 12,500 psi, and even more typically greater than about 15,000 psi .
  • the proppant does not typically suffer from complete failure of the polycarbodiimide coating due to shear or degradation when exposed to such temperatures and pressures.
  • the proppant is provided according to the method of forming the proppant as set forth above.
  • the subsurface fluid can be an unrefined petroleum or the like.
  • the method may include the filtering of other subsurface fluids not specifically recited herein, for example, air, water, or natural gas.
  • the fracture in the subsurface reservoir that contains the unrefined petroleum is identified by methods known in the art of oil extraction.
  • Unrefined petroleum is typically procured via a subsurface reservoir, such as a wellbore, and provided as feedstock to refineries for production of refined products such as petroleum gas, naphtha, gasoline, kerosene, gas oil, lubricating oil, heavy gas, and coke.
  • crude oil that resides in subsurface reservoirs includes impurities such as sulfur, undesirable metal ions, tar, and high molecular weight hydrocarbons.
  • impurities foul refinery equipment and lengthen refinery production cycles, and it is desirable to minimize such impurities to prevent breakdown of refinery equipment, minimize downtime of refinery equipment for maintenance and cleaning, and maximize efficiency of refinery processes. Therefore, filtering is desirable.
  • the hydraulic fracturing composition is pumped into the subsurface reservoir so that the hydraulic fracturing composition contacts the unfiltered crude oil.
  • the hydraulic fracturing composition is typically pumped into the subsurface reservoir at a rate and pressure such that one or more fractures are formed in the subterranean formation.
  • the pressure inside the fracture in the subterranean formation may be greater than about 5,000, greater than about 7,000, or even greater than about 10,000 psi, and the temperature inside the fracture is typically greater than about 70°F and can be as high as about 375°F depending on the particular subterranean formation and/or subsurface reservoir.
  • the proppant be a controlled-release proppant.
  • a controlled-release proppant while the hydraulic fracturing composition is inside the fracture, the polycarbodiimide coating of the proppant typically dissolves in a controlled manner due to pressure, temperature, pH change, and/or dissolution in the carrier fluid in a controlled manner, i.e., a controlled- release.
  • Complete dissolution of the polycarbodiimide coating depends on the thickness of the polycarbodiimide coating and the temperature and pressure inside the fracture, but typically occurs within about 1 to about 4 hours.
  • the controlled- release allows a delayed exposure of the particle to crude oil in the fracture.
  • the particle includes the active agent, such as the microorganism or catalyst
  • the particle typically has reactive sites that must contact the fluid, e.g. the crude oil, in a controlled manner to filter or otherwise clean the fluid.
  • the controlled-release provides a gradual exposure of the reactive sites to the crude oil to protect the active sites from saturation.
  • the active agent is typically sensitive to immediate contact with free oxygen.
  • the controlled-release provides the gradual exposure of the active agent to the crude oil to protect the active agent from saturation by free oxygen, especially when the active agent is a microorganism or catalyst.
  • the particle which is substantially free of the polycarbodiimide coating after the controlled-release, contacts the subsurface fluid, e.g. the crude oil.
  • the terminology “substantially free” means that complete dissolution of the polymeric coating has occurred and, as defined above, less than about 1% of the polymeric coating remains disposed on or about the particle. This terminology is commonly used interchangeably with the terminology “complete dissolution” as described above.
  • the particle upon contact with the fluid, the particle typically filters impurities such as sulfur, unwanted metal ions, tar, and high molecular weight hydrocarbons from the crude oil through biological digestion.
  • a combination of sands/sintered ceramic particles and microorganisms/catalysts are particularly useful for filtering crude oil to provide adequate support/propping and also to filter, i.e., to remove impurities.
  • the proppant therefore typically filters crude oil by allowing the delayed exposure of the particle to the crude oil in the fracture.
  • the filtered crude oil is typically extracted from the subsurface reservoir via the fracture, or fractures, in the subterranean formation through methods known in the art of oil extraction.
  • the filtered crude oil is typically provided to oil refineries as feedstock, and the particle typically remains in the fracture.
  • the particle may also be used to extract natural gas as the fluid from the fracture.
  • the particle particularly where an active agent is utilized, digests hydrocarbons by contacting the reactive sites of the particle and/or of the active agent with the fluid to convert the hydrocarbons in the fluid into propane or methane.
  • the propane or methane is then typically harvested from the fracture in the subsurface reservoir through methods known in the art of natural gas extraction.
  • Example 1 is a proppant comprising a particle having a polycarbodiimide coating disposed thereon.
  • the composition of Example 1 is disclosed below in Table 1.
  • a Particle A is first activated with the Adhesion Promoter, i.e., Particle A is pre-coated with the Adhesion Promoter at a concentration of 400 ppm by weight Particle A. More specifically, the Adhesion Promoter is dissolved in deionized water to form a solution comprising 0.5% weight percent Adhesion Promoter. The solution is mixed with the Particle A such that the Particle A is thoroughly wet-out by the solution. Once mixed, the particle having the solution thereon is heated, i.e., dried, in an oven set at 105°C.
  • the solution evaporates leaving the Particle A having the Adhesion Promoter coated thereon. That is, Particle A is activated with the Adhesion Promoter.
  • the Particle A now activated with the Adhesion Promoter, is pre-heated to a temperature of 215°C and added to a reaction vessel (a 1 -pint aluminum can.)
  • Isocyanate A, Isocyanate B, and TEP are mixed in a beaker to form a reaction mixture.
  • the reaction mixture is added to the reaction vessel, which contains the Particle A.
  • the reaction mixture and the Particle A are mixed with a 3" Jiffy mixer at 480 rpm on a drill press for 2 minutes. During agitation at these conditions, the reaction mixture forms a polycarbodiimide coating on the Particle A.
  • Example 1 is a proppant that comprises the Particle A having a polycarbodiimide coating disposed thereon.
  • Example 1 is described below in Table 1. The amounts in Table 1 are in grams. Table 1
  • Particle A is Ottawa sand, commercially available from U.S. Silica Company of
  • Adhesion Promoter is a silane commercially available from Momentive
  • Isocyanate A is polymeric isocyanate, commercially available from BASF Corp. of Corporation of Florham Park, NJ, under the tradename LUPRANATE ® M20.
  • Isocyanate B is 4,4'-diphenylmethane diisocyanate, commercially available from
  • TEP is tnethyl phosphate.
  • a Control Sample of Example 1 is stored at ambient conditions. Three samples of Example 1 are formed. A sample, Sample 1 of Example 1 is aged in an oven at 100°C for 19 hours while being exposed to air. A sample, Sample 2 of Example 1 is aged in an oven at 100°C for 33 days while being exposed to air. A sample, Sample 3 of Example 1 is submerged in deionized water and aged in an oven at 100°C for 33 days.
  • the Control Sample, Sample 1, Sample 2, and Sample 3 are evaluated by crush testing and thermal gravimetric analysis. [00102] The crush testing results are set forth in Table 2 below. The appropriate formula for determining percent fines is set forth in API RP60.
  • the Samples are sieved for ten minutes prior to testing crush strength to ensure that each Sample comprises individual proppant particles which are greater than sieve size 35.
  • the crush strength is tested by compressing a test weight of each Sample (sieved to > sieve size 35) in a test cylinder (having a diameter of 1.5 inches as specified in API RP60) at a loading density of 4 lb/ft .
  • E a ch Sample is compressed for 1 hour at 10,000 psi and 121°C (approximately 250°F). After compression, agglomeration is determined, and after each Sample is removed from the test cylinder, the Sample is sieved for 10 minutes and the percent fines is calculated.
  • Agglomeration is an objective observation of a Sample after crush strength testing as described above.
  • the Sample is assigned a numerical ranking between 1 and 10. If the Sample agglomerates completely, it is ranked 10. If the Sample does not agglomerate, i.e., it falls out of the cylinder after crush test, it is rated 1.
  • Samples 2 and 3 were also analyzed via thermal gravimetric analysis
  • TGA TGA over a temperature range of 5 to 750, °C in air at a heating rate of 10°C/min, using a TA Instruments Q5000 TGA.
  • the TGA results are set forth in Table 3 below.
  • Example 1 As described above, the crush strength, agglomeration, and thermal stability of Example 1 is excellent. Further, as is also described above, the performance properties of Example 1 , such as crush strength, agglomeration, and thermal stability, are consistent even after exposure to various conditions. [00107] It is to be understood that the appended claims are not limited to express and particular compounds, compositions, or methods described in the detailed description, which may vary between particular embodiments which fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, it is to be appreciated that different, special, and/or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims.
  • a range "of from 0.1 to 0.9" may be further delineated into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims.
  • a range such as "at least,” “greater than,” “less than,” “no more than,” and the like, it is to be understood that such language includes subranges and/or an upper or lower limit.
  • a range of "at least 10" inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange of from 25 to 35, and so on, and each subrange may be relied upon individually and/or collectively and provides adequate support for specific embodiments within the scope of the appended claims.
  • an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims.
  • a range "of from 1 to 9" includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1 , which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.

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Abstract

L'invention porte sur un agent de soutènement pour la fracturation hydraulique d'une formation souterraine, comprenant des particules et un enrobage de polycarbodiimide disposé sur chaque particule. L'enrobage de polycarbodiimide comprend le produit réactionnel d'un isocyanate amené à réagir en présence d'un phosphate de trialkyle. L'invention porte également sur un procédé de formation de l'agent de soutènement comprenant les étapes consistant à utiliser les particules, l'isocyanate et le phosphate de trialkyle. Le procédé comprend également des étapes consistant à faire réagir l'isocyanate en présence du phosphate de trialkyle pour former l'enrobage de polycarbodiimide et l'enrobage de chaque particule avec le revêtement de polycarbodiimide. L'invention porte également sur un procédé de fracturation hydraulique d'une formation souterraine utilisant l'agent de soutènement.
PCT/EP2012/051195 2011-01-31 2012-01-26 Agent de soutènement WO2012104190A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014045815A1 (fr) * 2012-09-20 2014-03-27 旭硝子株式会社 Agent de soutènement de puits et procédé de récupération d'hydrocarbures à partir d'une formation pétrolifère
US10385261B2 (en) 2017-08-22 2019-08-20 Covestro Llc Coated particles, methods for their manufacture and for their use as proppants

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2663737A (en) 1951-08-07 1953-12-22 Du Pont Substituted phosphacyclopentene oxides and process of preparing them
US2663738A (en) 1951-08-07 1953-12-22 Du Pont Substituted phosphacyclopentene sulfides and process of preparing them
US2853473A (en) 1956-08-27 1958-09-23 Du Pont Production of carbodiimides
US3056835A (en) 1961-07-24 1962-10-02 Du Pont Process for the preparation of carbodimides
US3152131A (en) 1961-11-28 1964-10-06 Du Pont Catalyst for preparing carbodiimides
US3384653A (en) 1965-03-31 1968-05-21 Upjohn Co Compositions of methylenebis (phenyl isocyanate) with trihydrocarbyl phosphates and preparation thereof
US3406197A (en) 1966-06-08 1968-10-15 Upjohn Co Transition metal carbonyl catalysts for converting organic isocyanates to carbodiimides
US3406198A (en) 1966-08-05 1968-10-15 Upjohn Co Triarylarsines as catalysts for converting isocyanates to carbodiimides
US3522303A (en) 1964-08-12 1970-07-28 Upjohn Co Phosphorous compounds
US4105643A (en) 1977-01-31 1978-08-08 The Upjohn Company Preparation of carbodiimide in presence of phospholene catalysts
US4105642A (en) 1977-01-31 1978-08-08 The Upjohn Company Preparation of carbodiimide in presence of phospholene catalysts
US4143063A (en) 1977-01-31 1979-03-06 The Upjohn Company Preparation of carbodiimide-containing polyisocyanates
US4284730A (en) 1980-02-07 1981-08-18 Basf Wyandotte Corporation Liquid carbodiimide- and uretonimine-isocyanurate-containing polyisocyanate compositions and microcellular foams made therefrom
WO2010049467A1 (fr) * 2008-10-29 2010-05-06 Basf Se Agent de soutènement

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2663738A (en) 1951-08-07 1953-12-22 Du Pont Substituted phosphacyclopentene sulfides and process of preparing them
US2663737A (en) 1951-08-07 1953-12-22 Du Pont Substituted phosphacyclopentene oxides and process of preparing them
US2853473A (en) 1956-08-27 1958-09-23 Du Pont Production of carbodiimides
US3056835A (en) 1961-07-24 1962-10-02 Du Pont Process for the preparation of carbodimides
US3152131A (en) 1961-11-28 1964-10-06 Du Pont Catalyst for preparing carbodiimides
US3522303A (en) 1964-08-12 1970-07-28 Upjohn Co Phosphorous compounds
US3384653A (en) 1965-03-31 1968-05-21 Upjohn Co Compositions of methylenebis (phenyl isocyanate) with trihydrocarbyl phosphates and preparation thereof
US3406197A (en) 1966-06-08 1968-10-15 Upjohn Co Transition metal carbonyl catalysts for converting organic isocyanates to carbodiimides
US3406198A (en) 1966-08-05 1968-10-15 Upjohn Co Triarylarsines as catalysts for converting isocyanates to carbodiimides
US4105643A (en) 1977-01-31 1978-08-08 The Upjohn Company Preparation of carbodiimide in presence of phospholene catalysts
US4105642A (en) 1977-01-31 1978-08-08 The Upjohn Company Preparation of carbodiimide in presence of phospholene catalysts
US4143063A (en) 1977-01-31 1979-03-06 The Upjohn Company Preparation of carbodiimide-containing polyisocyanates
US4284730A (en) 1980-02-07 1981-08-18 Basf Wyandotte Corporation Liquid carbodiimide- and uretonimine-isocyanurate-containing polyisocyanate compositions and microcellular foams made therefrom
WO2010049467A1 (fr) * 2008-10-29 2010-05-06 Basf Se Agent de soutènement

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Chemistry and Technology of Carbodiimides", 2007, JOHN WILEY & SONS, LTD.

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014045815A1 (fr) * 2012-09-20 2014-03-27 旭硝子株式会社 Agent de soutènement de puits et procédé de récupération d'hydrocarbures à partir d'une formation pétrolifère
JPWO2014045815A1 (ja) * 2012-09-20 2016-08-18 旭硝子株式会社 坑井用プロパント及び炭化水素含有地層からの炭化水素の回収方法
US10385261B2 (en) 2017-08-22 2019-08-20 Covestro Llc Coated particles, methods for their manufacture and for their use as proppants
US10647911B2 (en) 2017-08-22 2020-05-12 Covestro Llc Coated particles, methods for their manufacture and for their use as proppants
US10851291B2 (en) 2017-08-22 2020-12-01 Covestro Llc Coated particles, methods for their manufacture and for their use as proppants

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