Tue, 26 May 2015 08:00:00 EDTA composition, treatment fluid and method using hydrolyzable fines. A treatment fluid, which may optionally include a high solids content fluid (HSCF) and/or an Apollonianistic solids mixture, includes a fluid loss control agent comprising a dispersion of hydrolyzable fines, optionally with one or more of a surfactant, plasticizer, dispersant, degradable particles, reactive particles and/or submicron particles selected from silicates, γ-alumina, MgO, γ-Fe2O3, TiO2, and combinations thereof.
Tue, 26 May 2015 08:00:00 EDTSolid proppants are coated with a coating that exhibits the handling characteristics of a precured coating while also exhibiting the ability to form particle-to-particle bonds at the elevated temperatures and pressures within a wellbore. The coating includes a substantially homogeneous mixture of (i) at least one isocyanate component having at least 2 isocyanate groups, and (ii) a curing agent. The coating process can be performed with short cycle times, e.g., less than about 4 minutes, and still produce a dry, free-flowing, coated proppant that exhibits low dust characteristics during pneumatic handling but also proppant consolidation downhole for reduced washout and good conductivity.
Tue, 26 May 2015 08:00:00 EDTAn oxygen scavenger for completion brines effective and stable in high temperature subterranean formations. In one embodiment, the scavenger contains erythorbate and alkylhydroxlyamine.
Tue, 26 May 2015 08:00:00 EDTA pourable aqueous cement composition is disclosed. The cement composition comprises a hydraulic cement, water and a selectively removable material comprising a plurality of selectively corrodible metal powder particles dispersed within the cement or a nanomatrix powder compact, or a combination thereof. An article, including a downhole article, and more particularly a reconfigurable downhole article is disclosed. The article includes a hydraulic cement, wherein the hydraulic cement has at least partially set into a permanent form. The article also includes a selectively removable material dispersed within the cement, the selectively removable material comprising a plurality of selectively corrodible metal powder particles dispersed within the cement or a nanomatrix powder compact, or a combination thereof, wherein the selectively removable material is configured for removal in response to a predetermined wellbore condition.
Tue, 19 May 2015 08:00:00 EDTBiocidal compositions and their use in aqueous media, such as metalworking fluids, the compositions comprising a biocidal agent; and a non-biocidal primary amino alcohol compound of the formula (I); wherein R1, R2, R3, R4, and R5 are as defined herein.
Tue, 19 May 2015 08:00:00 EDTA spacer fluid comprises a fluid and a viscosity agent. The viscosity agent is a mixture of at least two polyvinylalcohol compositions. A first polyvinylalcohol composition comprises polyvinylalcohols having a first degree of hydrolysis and a second polyvinylalcohol composition comprises polyvinylalcohols having a second degree of hydrolysis. The first and second degrees of hydrolysis are substantially different such that the rheology of the spacer fluid is stable during temperatures changes.
Tue, 19 May 2015 08:00:00 EDTMethods for treating a subterranean formation penetrated by a wellbore where shear recovery time of viscoelastic surfactant treatment fluids is shorten by adding an effective amount of an fiber based rheology enhancer. The rheology enhancer also increases fluid viscosity. Further, the rheology enhancer also improves proppant settling. Some examples of surfactants are betaines and quaternary amines, and an example of fiber based rheology enhancer is polylactic acid fiber. The fluids are useful in oilfield treatments, as well as methods of preparing viscoelastic surfactant based fluids.
Tue, 19 May 2015 08:00:00 EDTFluid treatment systems and compositions are provided including (a) at least one material including (1) at least one carboxylic acid functional group and (2) at least one sulfur-containing group selected from the group consisting of sulfonyl functional groups, sulfonate functional groups and mixtures thereof; and (b) at least one scale control agent. The fluid treatment systems and compositions can be used to treat aqueous systems, for example as fracturing fluids for treating aqueous compositions found in subterranean formations. Methods for inhibiting formation and/or precipitation of calcium salts in an aqueous composition using the fluid treatment systems or compositions also are provided.
Tue, 19 May 2015 08:00:00 EDTFluid treatment systems and compositions are provided including (a) at least one material including (1) at least one carboxylic acid functional group and (2) at least one sulfur-containing group selected from the group consisting of sulfonyl functional groups, sulfonate functional groups and mixtures thereof; and (b) at least one friction reducing agent selected from the group consisting of guar gums, polyacrylamides, hydratable cellulosic materials, viscoelastic surfactants, and mixtures thereof. The fluid treatment systems and compositions can be used to treat aqueous systems, for example as fracturing fluids for use in fracturing subterranean formations. Methods for inhibiting formation and/or precipitation of metal oxides in an aqueous composition using the fluid treatment systems or compositions also are provided.
Tue, 19 May 2015 08:00:00 EDTThe current application discloses fluids and methods for treating a subterranean formation penetrated by a wellbore. In one aspect, there is provided a fluid comprising chitosan and titanate, where the fluid has an increased viscosity compared with a solution containing chitosan without titanate. In another aspect, there is provided a method of using such fluid to treat a subterranean formation penetrated by a wellbore. The method may comprise mixing chitosan and titanate in a carrying medium, forming a gel comprising chitosan and titanate, introducing the gel into a subterranean formation, and treating the subterranean formation with the gel.
Tue, 19 May 2015 08:00:00 EDTThe invention provides an oilfield suspending friction reducer treatment composition fluid comprising from about 0.001 weight percent to about 0.5 weight percent of a drag reducing surfactant; at least one drag reducing enhancer selected from the group consisting of polymeric drag reduction enhancers, monomeric drag reduction enhancers, and mixtures thereof.
Tue, 19 May 2015 08:00:00 EDTThe hydration of clays in drilling operations can be inhibited by employing an aqueous based drilling fluid containing from about 0.2 to about 5 wt % of a hydration inhibitor that comprises bis-hexamethylene-triamine, bis-hexamethylene-triamine salts, or mixtures thereof.
Tue, 19 May 2015 08:00:00 EDTA non-aqueous wellbore servicing fluid comprising a fluid loss additive wherein the fluid loss additive comprises the reaction product of (i) a functional polymer and (ii) an oligomerized fatty acid. A method of conducting an oil-field operation comprising placing a non-aqueous wellbore servicing fluid downhole wherein the non-aqueous wellbore servicing fluid comprises a fluid loss additive comprising the reaction product of (i) a functional polymer and (ii) an oligomerized fatty acid.
Tue, 19 May 2015 08:00:00 EDTUse of two different methods, either each by itself or in combination, to enhance the stiffness, strength, maximum possible use temperature, and environmental resistance of thermoset polymer particles is disclosed. One method is the application of post-polymerization process steps (and especially heat treatment) to advance the curing reaction and to thus obtain a more densely crosslinked polymer network. The other method is the incorporation of nanofillers, resulting in a heterogeneous “nanocomposite” morphology. Nanofiller incorporation and post-polymerization heat treatment can also be combined to obtain the benefits of both methods simultaneously. The present invention relates to the development of thermoset nanocomposite particles. Optional further improvement of the heat resistance and environmental resistance of said particles via post-polymerization heat treatment; processes for the manufacture of said particles; and use of said particles in the construction, drilling, completion and/or fracture stimulation of oil and natural gas wells are described.
Tue, 12 May 2015 08:00:00 EDTA well treatment composite which allows for the slow release of one or more well treatment agents into a subterranean formation and/or a wellbore penetrating the formation has a nano-sized calcined porous substrate (adsorbent) of high surface area onto which is applied the well treatment agent. The composites are suitable for use in such well treatment operations as hydraulic fracturing and sand control.
Tue, 12 May 2015 08:00:00 EDTAgents, chemicals and particles may be controllably released at remote locations, such as pre-selected or predetermined portions of subterranean formations, by binding or associating or trapping them with an association of micelles formed by a viscoelastic surfactant (VES) in an aqueous base fluid to increase the viscosity of the fluid. An internal breaker within the association of micelles disturbs the association of micelles at some later, predictable or predetermined time thereby reducing the viscosity of the aqueous viscoelastic treating fluid and releasing the agent, chemical or particle at a predetermined or selected location.
Tue, 12 May 2015 08:00:00 EDTMethods are provided that include, but are not limited to, methods of treating guar splits comprising: exposing guar splits to a treatment chemical to create treated guar splits, wherein the treatment chemical comprises at least one treatment chemical selected from the group consisting of: an aqueous salt solution; a caustic solution, and a derivatizing agent; and grinding the treated guar splits to create ground, treated guar splits.
Tue, 12 May 2015 08:00:00 EDTCrosslinked gelling agents employed during subterranean operations use electronically-modified boronic acids to enable higher operating temperatures while allowing reduced gelling agent loadings; the boronic acids having Formula I: X1 and X2 are independently selected from O, CH2, CH2O, OCH2, bond, and null, Y1 and Y2 are independently N or C, Ar is a 5- or 6-membered ring aryl or heteroaryl group with a link L to monomer unit M1, m is 1 or 2, n is 0, 1, 2, or 3, and each Z is independently an electron withdrawing group selected from nitro, ester, carboxylic acids, carboxylates, halogen, cyano, amide, acyl, alkylsulfonyl, arylsulfonyl, heteroarylsulfonyl, CF3, a quaternary ammonium salt, polyhaloalkyl, and carbamate, with the proviso that when n is 0, the link L between M1 and Ar includes an electron withdrawing group attached to Ar, and introducing the treatment fluids into subterranean formations.
Tue, 05 May 2015 08:00:00 EDTA method of increasing the fracture complexity in a treatment zone of a subterranean formation is provided. The subterranean formation is characterized by having a matrix permeability less than 1.0 microDarcy. The method includes the step of pumping one or more fracturing fluids into a far-field region of a treatment zone of the subterranean formation at a rate and pressure above the fracture pressure of the treatment zone. A first fracturing fluid of the one or more fracturing fluids includes a first solid particulate, wherein: (a) the first solid particulate includes a particle size distribution for bridging the pore throats of a proppant pack previously formed or to be formed in the treatment zone; and (b) the first solid particulate comprises a degradable material. In an embodiment, the first solid particulate is in an insufficient amount in the first fracturing fluid to increase the packed volume fraction of any region of the proppant pack to greater than 73%. Similar methods using stepwise fracturing fluids and remedial fracturing treatments are provided.
Tue, 28 Apr 2015 08:00:00 EDTMethods of making particulates for use in a subterranean application comprising: providing particulates of a settable composition comprising a cementitious material, a filler material, and an activator of the cementitious material; and pre-curing the particulates until the particulates reach a crush strength of about 50 psi or greater; and curing the pre-cured particulates at a temperature in the range of about 230° F. to about 600° F., so that at least a portion of the particulates comprise a newly formed crystalline phase.
Tue, 28 Apr 2015 08:00:00 EDTA well treatment fluid contains a viscoelastic surfactant and a viscosification activator. The viscosification activator enhances the viscosity of the well treatment fluid in contrast to a treatment fluid that does not contain a viscosification activator.
Tue, 28 Apr 2015 08:00:00 EDTA new general purpose foaming agent having application as drilling fluid foaming agents or as any foaming agent needed an a wide variety of applications is disclosed, where the agent includes at least one anionic surfactant, at least one cationic surfactant, and mixtures thereof and one or more zwitterionic compounds. A method for using the foaming agent in capillary coiled tubing application is also disclosed. The foaming agents can also include additive to augment the properties of the foaming agent for a given application.
Tue, 28 Apr 2015 08:00:00 EDTA polymer composition includes a base polymer comprising a hydrocarbon rubber, an acrylic copolymer, and a refined oil in which the acrylic polymer is dispersed. The polymer composition is swellable when treated with an aqueous medium, non-aqueous medium, or both. A sealing element for a flow channel includes an expandable section filled with a swellable composition that swells when treated with a swelling material. The swellable composition includes the polymer composition, and the swelling material may be aqueous, non-aqueous, or both.
Tue, 28 Apr 2015 08:00:00 EDTA method for breaking the viscosity of an aqueous fluid gelled with a water soluble polymer or a VES is disclosed. The method includes providing an aqueous fluid. The method also includes adding to the aqueous fluid, in any order: a water soluble polymer in an amount sufficient to form a gelled aqueous fluid having a viscosity, a water soluble oxidizing agent configured to generate free radicals and a plurality of metallic particles to produce a mixture comprising dispersed metallic particles dispersed within the gelled aqueous fluid, the metallic particles configured to dissolve in the gelled aqueous fluid and provide a reducing agent to accelerate the generation of free radicals. The method further includes dissolving the metallic particles in the gelled aqueous fluid to provide a source of at least one transition metal ion in an amount effective accelerate the generation of free radicals and reduce the viscosity.
Tue, 28 Apr 2015 08:00:00 EDTAqueous well treatment fluid compositions with biocidal activity are disclosed comprising a polymer for modifying fluid viscosity in the aqueous fluid, an organic monocarboxylic peracid being present in an anti-microbial amount of about 1 ppm to about 1000 ppm, and a controlled amount of hydrogen peroxide also being present. Peracetic acid is the preferred peracid. The viscosity-modifying polymer in the aqueous well treatment fluid composition may serve to reduce friction in the fluid or increase fluid viscosity. A method of using such compositions is also disclosed.
Tue, 28 Apr 2015 08:00:00 EDTMethods of treating a gas field fluid or oil field fluid is provided, the method comprising: a) adding glutaraldehyde to the gas field fluid or oil field fluid in an amount effective to reduce or inhibit microbial activity; and b) after a delay, adding 3,5-dimethyl-1,3,5-thiadiazinane-2-thione to the gas field fluid or oil field fluid.
Tue, 28 Apr 2015 08:00:00 EDTMethods of stabilizing water-sensitive clays in subterranean formations may include introducing a drill-in treatment fluid into at least a portion of a subterranean formation comprising water-sensitive minerals, where providing the drill-in treatment fluid comprises an aqueous-based fluid and a hydrophobically-modified cationic polymer; and allowing the hydrophobically-modified cationic polymer to at least partially coat the water-sensitive mineral.
Tue, 28 Apr 2015 08:00:00 EDTThe invention relates to a method for producing expanded glass granules. To this end, starting materials are provided, comprising 80% to 95% glass and 5% to 20% sodium silicate hydrate having a water of crystallization content between 1 and 2 wt %, in relation to the solids content. After the glass is ground, the starting materials are mixed, the ground starting materials are granulated into raw granules, and the raw granules are mixed with a release agent, the mixture comprising the raw granules and the release agent is heated to a processing temperature. In a first partial step, the pores on the surfaces of the particles of the raw granules are closed, and in a second partial step, the water of crystallization is dissolved from the sodium silicate hydrate and caused to thermally expand, whereby the particles of the raw granules expand and form the expanded glass granules.
Tue, 28 Apr 2015 08:00:00 EDTA Blowout Preventer comprising a housing, one or more magnets and a magnetic fluid is described. More particularly, a Magnetorheological Blowout Preventer with a Magnetorheological Ram Head that conforms to virtually any cross sectional shape is described with ultra-reliable termination of natural gas and/or oil effluent flow resulting.
Tue, 21 Apr 2015 08:00:00 EDTA spacer fluid comprising: (a) water; and (b) an alkyl polyglycoside derivative, wherein the alkyl polyglycoside derivative is selected from the group consisting of sorbitan fatty acids; functionalized sulfonates, functionalized betaines, an inorganic salt of any of the foregoing, and any combination of any of the foregoing. Preferably, the spacer fluid additionally comprises a solid particulate, such as a weighting agent. A method of displacing an oil-based drilling mud from a portion of a well comprising the steps of: (A) forming the spacer fluid; and (B) introducing the spacer fluid into the well.
Tue, 21 Apr 2015 08:00:00 EDTApparatus and compositions for reducing the viscosity of a gelled fluid is provided. In one embodiment, a viscosity reducing microbe is disposed in a capsule and added to the gelled fluid. The gelled fluid may include a thickening agent adapted to increase its viscosity. Upon release from the capsule, the microbe begins to digest the thickening agent in the gelled fluid and/or releases enzymes that that breakdown the thickening agent.
Tue, 21 Apr 2015 08:00:00 EDTRemoving an asphaltene particle from a substrate includes contacting a silicate nanoparticle with a chemical group to form a functionalized silicate nanoparticle, the chemical group includes a first portion; and a second portion comprising an aromatic moiety, the first portion being bonded to the silicate nanoparticle; contacting the asphaltene particle with the functionalized silicate nanoparticle, the asphaltene particle being disposed on the substrate; interposing the functionalized silicate nanoparticle between the asphaltene particle and the substrate; and separating the asphaltene particle from the substrate with the functionalized silicate nanoparticle to remove the asphaltene particle. A composition includes a functionalized silicate nanoparticle comprising a reaction product of a silicate nanoparticle and an aromatic compound; and a fluid. The aromatic compound includes a chemical group that includes a first portion, the first portion being directly bonded to the silicate nanoparticle in the functionalized silicate nanoparticle; and a second portion including an aromatic moiety.
Tue, 21 Apr 2015 08:00:00 EDTMethods of inhibiting corrosion of a metal surface in a well or pipeline are provided. The methods include the steps of: (a) forming a fluid of: (i) an aqueous acid solution; and (ii) inulin; and (b) introducing the fluid into the well or pipeline. The methods have wide application in various kinds of operations involved in the production or transportation of oil and gas, such as acid stimulation or remedial treatment in a pipeline.
Tue, 21 Apr 2015 08:00:00 EDTShaped particulates which have been compressed from a composite of a well treatment agent and adsorbent in a matrix may be introduced into horizontal or deviated oil or gas wells. The well treatment agent of the shaped pellets may be used to prevent and/or control the formation of deposits in a production well.
Tue, 21 Apr 2015 08:00:00 EDTA method for recovering oil from a fractured reservoir having an oil-wettable matrix and comprising at least one injection well and one production well. This method comprises the following steps in such order: a)injecting by an injection well a solution of viscosity-enhancing surfactants, capable of penetrating into the array of fractures, having limited interaction with the matrix, and creating a plug in situ to reduce the perviousness of the fractures and to promote the passage of the solution of step b) into the matrix; b) injecting by an injection well a solution of surfactants, capable of interacting with the matrix to make water-wettable and to extract the oil therefrom; c) injecting by an injection well an aqueous solution to increasing the surface tension, impregnating the matrix and, after the plug in step a) is dissolved by the oil, driving the oil toward the production well.
Tue, 14 Apr 2015 08:00:00 EDTUse of two different methods, either each by itself or in combination, to enhance the stiffness, strength, maximum possible use temperature, and environmental resistance of thermoset polymer particles is disclosed. One method is the application of post-polymerization process steps (and especially heat treatment) to advance the curing reaction and to thus obtain a more densely crosslinked polymer network. The other method is the incorporation of nanofillers, resulting in a heterogeneous “nanocomposite” morphology. Nanofiller incorporation and post-polymerization heat treatment can also be combined to obtain the benefits of both methods simultaneously. The present invention relates to the development of thermoset nanocomposite particles. Optional further improvement of the heat resistance and environmental resistance of said particles via post-polymerization heat treatment; processes for the manufacture of said particles; and use of said particles in the construction, drilling, completion and/or fracture stimulation of oil and natural gas wells are described.
Tue, 14 Apr 2015 08:00:00 EDTEmbodiments relate to systems and methods for introduction of fluids comprising kiln dust into a wellbore through a bottom hole assembly. An embodiment discloses a method comprising: drilling a wellbore in a subterranean formation using a bottom hole assembly; and pumping a treatment fluid into the wellbore through the bottom hole assembly, wherein the treatment fluid comprises a kiln dust and water.
Tue, 14 Apr 2015 08:00:00 EDTA variety of methods and compositions are disclosed, including, in one embodiment, a method of treating a well comprising: providing a treatment fluid comprising a base fluid and a blended cementitious component, wherein the blended cementitious component comprises kiln dust from two or more different sources; and introducing the treatment fluid into a well bore.
Tue, 14 Apr 2015 08:00:00 EDTCompositions and methods are given for delayed breaking of viscoelastic surfactant gels inside formation pores, particularly for use in hydraulic fracturing. Breaking inside formation pores is accomplished without mechanical intervention or use of a second fluid. Bromate oxidizing agents are used along with selected breaking activators for the bromate breaking compounds. Useful bromate breaking activators include acid-generating breaking activators, oxidizing sulfur containing breaking activators, and reducing agent breaking activators.
Tue, 14 Apr 2015 08:00:00 EDTMethods and compositions are provided that relate to cement compositions comprising sub-micron calcium carbonate and latex. An embodiment includes a cement composition comprising: cement, water, sub-micron calcium carbonate having a particle size in a range of from greater than 100 nanometers to about 1 micron, and latex.
Tue, 14 Apr 2015 08:00:00 EDTEmbodiments of the invention provide a drilling, drill-in, and completion water-based mud composition containing micro or nanoparticles for use in hydrocarbon drilling. The water-based drilling mud composition includes water present in an amount sufficient to maintain flowability of the water-based drilling mud composition, and drilling mud, which includes particles. The particles are selected from microparticles, nanoparticles, and combinations thereof. The water-based drilling mud composition also includes an effective amount of a multi-functional mud additive, which includes psyllium seed husk powder. The water-based drilling mud composition is operable to keep the particles stabilized and dispersed throughout the drilling mud composition in the absence of a surfactant.
Tue, 14 Apr 2015 08:00:00 EDTIn a method of gravel packing a wellbore in a subterranean formation, the wellbore comprising a cased section and an uncased section, the method may include pumping into the wellbore a gravel pack composition comprising gravel and a carrier fluid comprising an invert emulsion fluid, where the invert emulsion fluid may comprise: an oleaginous external phase; a non-oleaginous internal phase, wherein a ratio of the oleaginous external phase and non-oleaginous internal phase is less than 50:50 and an emulsifier stabilizing the oleaginous external phase and the non-oleaginous internal phase.
Tue, 14 Apr 2015 08:00:00 EDTMethods for enhancing acetoclastic methanogenesis in subterranean geologic formations. The methods may include accessing a microorganism consortium in the formation, and assessing the consortium for acetoclastic methanogenic activity. The methods may further include modifying the formation environment based on the consortium assessment to increase methane production from acetoclastic methanogenic pathways used by the consortium. The modifications to the formation environment may include introducing an amendment and/or introducing acetoclastic microorganisms to the formation environment.
Tue, 07 Apr 2015 08:00:00 EDTA method for controlling the loss of drilling fluid from an oil well borehole into formations penetrated by a drill bit is disclosed by which resilient graphitic carbon particles having a resiliency greater than about 130% rebound after compression to 10,000 psi; a degree of graphitization greater than 85%, as measured by d002 using XRD; an average pore size larger than 0.035 micron; and an aspect ratio smaller than 0.63 are added to the drilling fluid.
Tue, 07 Apr 2015 08:00:00 EDTMethods of drilling wellbores, placing proppant packs in subterranean formations, and placing gravel packs in wellbores may involve fluids, optionally foamed fluids, comprising nanoparticle suspension aids. Methods may be advantageously employed in deviated wellbores. Some methods may involve introducing a treatment fluid into an injection wellbore penetrating a subterranean formation, the treatment fluid comprising a base fluid, a foaming agent, a gas, and a nanoparticle suspension aid; and producing hydrocarbons from the subterranean formation via a production wellbore proximal to the injection wellbore.
Tue, 07 Apr 2015 08:00:00 EDTA method includes introducing a treatment fluid including a first polymer gel into a subterranean formation to generate a production fluid having an aqueous portion and a hydrocarbon portion, treating the aqueous portion of the production fluid with chlorine dioxide to separate additional hydrocarbons from the aqueous portion, and adjusting the viscosity of the treated aqueous portion prior to introducing the treated aqueous portion back into the subterranean formation.
Tue, 31 Mar 2015 08:00:00 EDTA crosslinking composition for hydrocarbon gels containing phosphate ester gelling agents comprising a modified imidazoline or pyrimidine including an alkyl group (or unsaturated carbon chain) or of 10 to 22 carbon atoms, a polyamine, and ferric sulfate. The method of making the crosslinking agent features adding the polyamine after reaction of the other ingredients; unique gels formed with the crosslinking agent are particularly effective for LNG at very cold temperatures.
Tue, 31 Mar 2015 08:00:00 EDTCompositions that swell on contact with water contain a non-swellable thermoplastic or thermoset polymer and a swellable inorganic compound. In particular, the compositions are suitable for use in subterranean wells such as those used in the oil and gas industry. The polymer may be polypropylene and the inorganic compound may be magnesium oxide.
Tue, 31 Mar 2015 08:00:00 EDTThe present invention relates to environmentally friendly compositions and methods for removing or suppressing metal ions in waters, flowback waters, and produced waters to make such waters suitable for subsequent use in oil-field applications and for delinking metal cross-linked gelling agents. One embodiment of the present invention provides a method of providing a competitive binder and allowing the competitive binder to interact with interfering metal ions in a flowback fluid to suppress or remove interfering metal ions.
Tue, 31 Mar 2015 08:00:00 EDTSolid proppants are coated with a phenol-urethane coating in one or more layers by a method comprising coating a proppant solid and then curing the coated proppant under conditions sufficient to substantially cure said proppant, wherein said coating comprises a substantially homogeneous mixture of (i) an isocyanate component having at least 2 isocyanate groups, (ii) an amine reactant, and optionally (iii) an amine that is a latent curing agent for said isocyanate.