Abstract: After installing an inventive tool attached to production tubing in a well, the well can be gravel packed without the use of a well intervention unit. The tool isolates a productive interval and diverts tubing-conveyed sand slurry towards an annular location by means of a port and an openable passageway restrictor. The entraining fluid component of the diverted sand slurry in the annular location is allowed to re-enter the production tubing through a first screen while the separated sand drops to the annular location to be packed in an axial direction. Rupture of a plug then allows the separated sand to be packed in an axial direction.

Abstract: A repositionable apparatus for perforating and gravel packing an underground well uses gravity or other means to reposition the apparatus instead of a conventional wireline or work string attached to a rig. Perforating and packing can be accomplished without a rig after the apparatus is initially placed and set in the well. One embodiment of the inventive apparatus uses a perforating gun assembly, a connected ported sub above the gun assembly, a translating annulus packer above the ported sub, a circumferential screen located above the packer, blank pipe connected above the screen, an openable port above the blank tubular pipe, and a second translating annulus packer attached to the blank tubular.

Abstract: The present invention provides improved methods of consolidating particulate material in a subterranean zone penetrated by a well bore. The methods basically comprise the steps of coating the particulate material with a hardenable resin composition and irradiating the hardenable resin composition coating on the particulate material with microwaves to thereby accelerate the hardening of the resin composition whereby the particulate material is rapidly consolidated into a stationary permeable mass.

Abstract: A method of cementing a casing in a well drilled in the ground comprises injecting a liquid material comprising phenol-formol resin from the surface, wherein the resin is modified by means of a determined amount of furfuryl alcohol, and an amount of mineral filler unreactive towards the resin is added. The invention further relates to a thermosetting cementing material comprising phenol-formol resin. The resin is modified by means of an amount of furfuryl alcohol and comprises at least a proportion of an unreactive granular filler.

Abstract: The present invention provides a method of treating a subterranean formation with a particulate laden fluid whereby particulate flowback is reduced or prevented. The method includes the steps of providing a fluid suspension including a mixture of a particulate, a tackifying compound and a multifunctional material, pumping the suspension into a subterranean formation and depositing the mixture within the formation whereby the tackifying compound retards movement of at least a portion of the particulate within the formation upon flow of fluids from the subterranean formation and said multifunctional material subsequently reacts with said tackifying compound to consolidate at least a portion of said particulate within said formation.

Abstract: The present invention relates to improved methods and compositions for consolidating unconsolidated subterranean zones. The compositions of the invention are low viscosity hardenable epoxy resin compositions which are basically comprised of an epoxy resin, a N-methyl-2-pyrrolidone diluent and an effective amount of a hardening agent.

Abstract: A deformable well screen for preventing migration of solid particles into a hydrocarbon production well is disclosed, the screen including at least one substantially tubular filter layer of which the sieve opening size remains fairly constant during or after expansion and/or other deformation of the screen. Optionally the screen also includes a series of circumferentially scaled filter segments that are arranged around an expandable slotted tube, an expandable slotted tube of which the slots are filled with resin coated granules, an expandable slotted tube with micro-slots, an assembly of woven metal wire screens that are sintered together and/or a synthetic geotextile fabric.

Abstract: The present invention relates to improved methods of sealing openings in a well bore penetrating a subterranean zone into which fluids contained in the well bore are lost or from which fluids undesirably flow into the well bore. The methods basically comprise the steps of preparing a hardenable epoxy sealing composition comprising an epoxide containing liquid and a hardening agent, placing the epoxy sealing composition by way of the well bore into the openings and into the subterranean zone and allowing the epoxy composition to harden whereby the well bore is sealed.

Abstract: The present invention provides methods of protecting ferrous metal well tubular goods and the like disposed in a well bore penetrating a subterranean formation from corrosion. The method basically includes the steps of introducing a liquid or solution of a tackifying compound having ferrous metal corrosion inhibition properties into the well bore whereby the tackifying compound is coated onto the tubular goods thereby providing extended corrosion protection to the tubular goods. Thereafter, formation fluids are produced from the subterranean formation.

Abstract: Disclosed is an electrokinetic soil decontamination system that uses special electrode wall configurations, treatment wall configurations, and a combination electrode/treatment wall. A special emplacement method for all the flowable wall materials is used and special wall material compositions are disclosed.

Abstract: The present invention provides improved well drilling fluids containing epoxy sealants and methods of drilling well bores using the drilling fluids. The drilling fluids basically include a base fluid selected from the group of water and oil, a viscosity increasing material and a hardenable epoxy sealant composition which becomes part of the filter cake formed on the walls of the well bore and hardens therein whereby the filter cake is consolidated into a stable solid mass.

Abstract: Improved methods of propping a fracture in a subterranean zone whereby the subsequent flow-back of the proppant is prevented are provided. The methods basically include the steps of placing a mixture of fibrous bundles and the proppant in the fracture while maintaining the fracture open and then allowing the fracture to close on the mixture of fibrous bundles and proppant.

Abstract: The present invention provides a method of treating a wellbore penetrating a subterranean formation with a treatment fluid whereby fine particulate flowback is reduced or prevented. The method includes the steps of providing a fluid suspension including a mixture of a particulate coated with a tackifying compound, pumping the suspension into a subterranean formation and depositing the mixture within the formation whereby the tackifying compound retards movement of at least a portion of any fine particulate within the formation upon flow of fluids from the subterranean formation through the wellbore. Alternatively, the tackifying compound may be introduced into a subterranean formation in a diluent containing solution to deposit upon previously introduced particulates to retard movement of such particulates and any fines subject to flow with production of fluids from the subterranean formation.

Abstract: The present invention provides a method of treating a subterranean formation with a particulate laden fluid whereby particulate flowback is reduced or prevented. The method includes the steps of providing a fluid suspension including a mixture of a particulate, a tackifying compound and a hardenable resin, pumping the suspension into a subterranean formation and depositing the mixture within the formation whereby the tackifying compound retards movement of at least a portion of the particulate within the formation upon flow of fluids from the subterranean formation and said hardenable resin subsequently consolidates at least a portion of said particulate within said formation.

Abstract: The present invention provides a method of treating a subterranean formation with a particulate laden fluid whereby particulate flowback is reduced or prevented. The method includes the steps of providing a fluid suspension including a mixture of a particulate upon which at least a partial coating of a tackifying compound is formed as a result of admixture of the tackifying compound therewith, pumping the suspension into a subterranean formation and depositing the mixture within the formation whereby the tackifying compound retards movement of at least a portion of the particulate within the formation upon flow of fluids from the subterranean formation.

Abstract: The present invention provides a method of treating a subterranean formation with a particulate laden fluid whereby particulate flowback is reduced or prevented. The method includes the steps of providing a fluid suspension including a mixture of a particulate upon admixture therewith, pumping the suspension into a subterranean formation and depositing the mixture within the formation whereby the tackifying compound retards movement of at least a portion of the particulate within the formation upon flow of fluids from the subterranean formation.

Abstract: The present invention provides a method of treating a wellbore penetrating a subterranean formation with a treatment fluid whereby fine particulate flowback is reduced or prevented. The method includes the steps of providing a fluid suspension including a mixture of a particulate coated with a tackifying compound, pumping the suspension into a subterranean formation and depositing the mixture within the formation whereby the tackifying compound retards movement of at least a portion of any fine particulate within the formation upon flow of fluids from the subterranean formation through the wellbore. Alternatively, the tackifying compound may be introduced into a subterranean formation in a diluent containing solution to deposit upon previously introduced particulates to retard movement of such particulates and any fines subject to flow with production of fluids from the subterranean formation.

Abstract: An improved method for acidizing an oil bearing formation in the presence of water bearing zones having high permeability is described. An aqueous fluid is pumped into the formation preceding the injection of stimulation material. This fluid contains hydroxyethylcellulose, a fluorescent dye and an organic acid anhydride, which during hydrolysis reduces the pH and the viscosity of the solution making it retrievable without damage to the formation.

Abstract: In one embodiment, an epoxy resin composition is provided comprising: an epoxy resin and a partially reduced aromatic amine hardening agent. In another embodiment, a well treating composition is provided comprising: an epoxy resin; a partially reduced aromatic amine hardening agent; a solid particulate material; and a carrier fluid. In yet another embodiment, a method of treating a subterranean formation is provided. The inventive method comprises the step of placing the inventive well treating composition into the formation.

Abstract: The invention involves an assembly, specifically beneficial in deviated well-bores, which allows running into the wellbore with the complete completion assembly. The completion assembly includes one or more screens which may be pre-packed. Initially, a material which sets to form a permeable mass is deposited in the annular space outside the screens. After such material is deposited, cement or other sealing material is pumped into the annular space above the screens to complete the completion process. As a result, in one trip the deviated wellbore is completed with the permeable material deposited outside the screen or screens and cement being disposed in the annular space above the permeable material. Production can then begin.

Abstract: The addition of an adhesive coated material in intimate mixture with particulates for fracturing, gravel packing or other formation treatments decreases or substantially eliminates the flowback of particulates whether proppants or formation fines while stabilizing the particulate within the formation. Preferred adhesive coated materials include glass or ceramic fibers, polyolefins, polyamides, polyvinyls and cellulose derivatives in the form of particles, ribbons, fibers or flakes.

Abstract: Methods of combating production problems in wells containing defective gravel packs are provided. The methods basically comprise forming at least one perforation in the well bore extending from the well bore through the defective gravel pack and into the producing formation, forming at least one fracture containing proppant material in the formation communicating with the perforation and consolidating the proppant material in the fracture.

Abstract: The addition of a thermoplastic material in intimate mixture with particulates for fracturing, gravel packing or other formation treatments decreases or substantially eliminates the flowback of particulates whether proppants or formation fines while stabilizing the particulate within the formation. Preferred thermoplastic materials include polyolefins, polyamides, polyvinyls and cellulose derivatives in the form of particles, ribbons or flakes.

Abstract: Fracturing, frac-pack, and gravel packing procedures are provided which utilize a treating composition comprising a carrier fluid and a particulate blend. The particulate blend consists essentially of a large particulate material and a small particulate material. The large particulate material consists essentially of particles smaller than about 4 mesh but not smaller than about 40 mesh. The small particulate material consists essentially of particles smaller than about 16 mesh but not smaller than about 100 mesh. The small particulate material is present in the particulate blend in an amount in the range of from about 5% to about 60% by weight based on the amount of the large particulate material present in the particulate blend. A prepacked screening device including a large particulate/small particulate blend of the type just described is also provided.

Abstract: A cement for forming a gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the borehole's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous silicate solution is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid is introduced into the interval. Thereafter, a water-miscible organic solvent containing an alkylpolysilicate is injected into the interval. A permeability retaining silica cement is formed in the interval thereby making a gravel pack. Injection of the aqueous silicate and organic solvent containing an alkylpolysilicate is continued until the interval has been consolidated by the silica cement to an extent sufficient to exclude sand and formation fines.

Abstract: A well treating composition comprising: a gelled carrier; a particulate material; an epoxy resin system including at least one epoxy resin; and a finely-divided hardening agent which, when dissolved, is operable for hardening the epoxy resin. The finely-divided hardening agent is dispersed in the epoxy resin system. A method of treating a subterranean zone located in a well comprising the steps of: (a) preparing the above-described treating composition; (b) injecting the treating composition into the well such that the treating composition is placed in the subterranean zone; and (c) maintaining the finely-divided hardening agent under conditions such that, prior to injecting the treating composition into the well, the finely-divided hardening agent does not substantially dissolve.

Abstract: The present invention provides a method of gravel packing a subterranean formation using a gel of a graft copolymer of a hydroxyalkyl cellulose prepared by a redox reaction with vinyl phosphonic acid. The gel is formed by hydrating the graft copolymer in an aqueous liquid. The gel in crosslinked by the addition of a crosslink initiator comprising a Lewis base or Bronsted-Lowry base, which is substantially free of polyvalent metal ions, to the gel in an amount sufficient to effect crosslinking of the graft copolymer. The viscosity of the crosslinked gel is reduced by contacting the gel with an acidic fluid whereby the pH of the gel is caused to decrease. The reduction in gel viscosity facilitates formation of the gravel pack.

Abstract: A method for forming a consolidated gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the borehole's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous hydroxide solution is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid slug is injected into the interval. Thereafter, a water-miscible organic solvent slug containing alkylpolysilicate is injected into the interval. A permeability retentive silica cement is formed in the interval thereby making a consolidated gravel pack. Injection of the aqueous hydroxide and alkylpolysilicate slugs is continued until silica cement has been deposited to an extent sufficient to exclude formation fines and sand.

Abstract: Perforation tunnels and other voids or spaces in earth formations in communication with wells are sealed more effectively by injecting and pre-packing resin-coated particulates (sand) into such tunnels or voids and allowing the sand to consolidate to form a substantially rigid, permeable mass. A lead slurry of relatively fine grained cement is then injected to fill the interstices formed in the permeable material occupying the tunnels or voids. A larger or more coarse grain cement is then injected to form a substantially impermeable, rigid filter cake at the interface of the wellbore and the permeable mass to prevent loss of cement slurry out of the tunnels or voids before the cement is set. Vertical and deviated or generally horizontal wellbores having perforation tunnels or voids which suffer unwanted cement drainage prior to setting of conventional oil well cements are more effectively sealed by the sequential injection of the permeable material followed by injection of settable cement slurries.

Abstract: A well penetrator has a housing moveable down a well casing with a radially moveable punch being supported in the housing for movement between retracted and extended positions; a fluid jet is discharged from the outer end of the punch with liquid for the jet coming from a tube fixedly positioned at one end in the housing and held in slightly bowed condition when the punch is retracted to permit movement of the punch to its extended position from its retracted condition without the creation of excessive force on this metal tube. The jet creates a bulbous drumstick shaped cavity in the earth which is packed with a gravel slurry which hardens and cannot move into the casing due to the bulbous shape of the hardened slurry mass. Similar procedures are employed using a hose or lance with a nozzle at its outer end; one nozzle embodiment includes radial jets activated to transversely enlarge the cavity at a location spaced from the casing.

Abstract: A substituted alkoxy benzene having the formula ##STR1## wherein R, R.sub.1, R.sub.2 and R.sub.3 are each a hydrocarbon radical having from 1 to 8 carbon atoms and x is 0 or 1 is provided. The substituted alkoxy benzene is very useful as a wetting aid for enhancing the ability of hardenable polyepoxide resin compositions to coat and bond to material (e.g., particulate material) in high temperature applications. The substituted alkoxy benzene does not significantly accelerate the curing rate of the resins. A polyepoxide resin composition for coating and bonding to a material, a composition useful for forming a hard permeable mass in a remote location and a method of continuously forming and suspending consolidatible resin composition coated particulate material in a gelled aqueous carrier liquid and transporting the coated particulate material to a remote location where the material is consolidated are also provided.

Abstract: A method of completing a horizontal well in an incompetent formation includes running a pipe string into the horizontal well bore, pumping a hardenable permeable material into the horizontal well bore, allowing the hardenable material to set up and then drilling up at least part of the pipe string. The hardenable permeable material may be resin coated sand providing sand control for the incompetent formation. In the event the horizontal bore hole vertically meanders out of a desired path and falls below an oil-water contact or rises above a gas-oil contact, that portion of the pipe string located out of the desired path is not drilled up thereby deterring production of undesired formation fluids.

Abstract: A method for forming a gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the boreholes's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous silicate slug is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid is introduced into the interval. Thereafter, a water-miscible organic solvent slug, containing an alkylpolysilicate and an inorganic or organic salt or a chelated calcium mixture, is injected into the interval. A permeability retaining silicate cement is formed in the interval thereby making a gravel pack.

Abstract: A method for gravel packing perforations in a wellbore where an acid is directed into the perforations so as to dissolve formation fines in channels contained in said perforations. The acid is of a strength sufficient to dissolve said fines. After the fines are dissolved, a sand consolidation agent is introduced into the perforations before the channels can be filled with formation fines. The consolidation agent remains in the perforations for a time sufficient to form a cement in situ which cement has permeability retentive characteristics. The cement forms pores of a size sufficient to exclude formation fines from the wellbore. Thereafter, a substantially fines free hydrocarbonaceous fluid is produced from the wellbore.

Abstract: A method for forming a consolidated gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the borehole's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous hydroxide solution is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid slug is injected into the interval. Thereafter, a water-miscible organic solvent slug containing alkylpolysilicate is injected into the interval. A permeability retentive silica cement is formed in the interval thereby making a consolidated gravel pack. Injection of the aqueous hydroxide and alkylpolysilicate slugs is continued until silica cement has been deposited to an extent sufficient to exclude formation fines and sand.

Abstract: Methods of completing a well bore having a conduit disposed therein where portions of the well bore and conduit are positioned substantially horizontally in a subterranean producing formation are provided. A hardenable resin composition coated particulate solid material is placed in the annulus between the sides of the well bore and the conduit, and the resin composition is caused to harden whereby the particulate material is consolidated into a hard permeable mass. An aqueous cement slurry is introduced into the permeable consolidated particulate material whereby horizontal sections thereof are isolated which allows tests and/or treatments in selected portions of the horizontal well to be performed.

Abstract: A method for forming a gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the borehole's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous silicate solution is injected into said interval. Next, a spacer volume of a water-immiscible hydrocarbonaceous liquid is introduced into the interval. Thereafter, a water-miscible organic solvent containing an alkylpolysilicate is injected into the interval. A permeability retaining silica cement is formed in the interval thereby making a gravel pack. Injection of the aqueous silicate and organic solvent containing an alkylpolysilicate is continued until the interval has been consolidated by the silica cement to an extent sufficient to exclude sand and formation fines.

Abstract: A method for producing substantially sand or fines free hydrocarbonaceous fluids from a wellbore which is initially gravel packed. Thereafter, an acid is directed into the wellbore so as to dissolve formation fines in channels contained in perforations communicating with a productive interval of the formation. The acid is of a strength sufficient to dissolve said fines. After the fines are dissolved, a sand consolidation agent is introduced into the perforations before the channels can be filled with formation fines. The consolidation agent remains in the perforations for a time sufficient to form a cement in situ which cement has permeability retentive characteristics. The cement forms pores of a size sufficient to exclude formation fines from the wellbore.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: A composition and method for consolidating proppant or gravel for propping fractures about, or for gravel packs for sand control in, wells in subterranean formations characterized by an improvement in which there is used a combination of reactants, including a capped diisocyanate that will produce polyurethane and coat the catalyst in situ. Also disclosed are specific examples of satisfactory frac fluids, diluents and catalysts for both a specially designed one-pass system and, preferably, a two-pass system of putting and consolidating the proppant in a fracture.

Abstract: A method for gravel packing a wellbore where a resin-coated sand or "gravel" is utilized. First, the wellbore is perforated at the productive interval in a manner sufficient to hydraulically fracture the formation. Afterwards, the formation is hydraulically fractured via a frac fluid containing a resin-coated sand. During this fracturing operation, a resultant fracture is propped with the resin-coated sand. The frac fluid is pumped down the wellbore until "screen out" occurs at perforations in the wellbore. The resin-coated sand is allowed to remain in the fracture, perforations, and wellbore until a permeable, porous consolidated mass is formed. After the mass has formed, excess consolidated sand is removed from the wellbore. When the formation is produced, formation solids are contained by the consolidated mass in the fracture and perforations.

Abstract: A method for forming a gravel pack in a washed-out interval is provided where a borehole penetrates an unconsolidated or loosely consolidated oil or gas reservoir which is likely to introduce substantial amounts of sand into the borehole. After perforating the borehole's casing at a washed-out interval of the formation, sand is introduced into the interval. Afterwards, an aqueous solution of potassium silicate is injected into said interval. Thereafter, an alcoholic solution of hydrated calcium chloride is injected into the interval. A permeability retaining calcium silicate cement is formed in the interval thereby making a gravel pack. Injection of the potassium silicate and hydrated calcium chloride solutions is continued until the porosity of the interval has been reduced by the calcium silicate cement to an extent sufficient to exclude formation fines and sand.

Abstract: A method of preparing high density particulate slurries is provided whereby slurries containing in excess of 23 pounds of particulate per gallon of fluid can be introduced into a subterranean formation. In accordance with the method, a viscosified pad fluid is introduced into a wellbore to create a filter cake in a desired zone within a subterranean formation. The high density slurry then is introduced into the formation to substantially fill any annular space present without significant settling. This permits the coating of the entire exterior surface of highly deviated casing exposed within a wellbore.

Abstract: A composition and method for consolidating proppant or gravel for propping fractures about, or for gravel packs for sand control in, wells in subterranean formations characterized by an improvement in which there is used a urethane quasi prepolymer consisting of dipropylene glycol and excess polymeric methylene diphenylene diisocyanate in a diluent, allowing to stand to form oligomers of polyurethane chains and admixing the urethane quasi prepolymer and diluent with a proppant and oil-based frac fluid and admixing a catalyst with the admixture of proppant and prepolymer and allowing to stand in the fractures, or well, until consolidation occurs. Also disclosed are specific examples of satisfactory frac fluids, diluents and catalysts and appropriate procedures for consolidation in one- or two-passes.

Abstract: A method to improve well performance in gravel packed wells. In this method a wellbore is perforated with four to twelve shots per foot. Thereafter, hydraulic fracturing is conducted in the formation via a viscous fracturing fluid, having a 20/40 mesh proppant therein, which creates and props a fracture. Hydraulic fracturing is ceased and a gravel pack is placed in the wellbore. The gravel pack contains gravel of a mesh smaller than the fracturing fluid proppant, e.g. 40/60 mesh. The larger mesh proppant in the fracture forms a screen which prevents entry of most fines or sand into the fracture while the smaller mesh proppant removes fines or sand escaping the fracture screen. Therefore, this combination removes substantially all fines or sand from hydrocarbonaceous fluids produced to the surface.

Abstract: A mixture of a liquid epoxy material and a hardener is selectively placed in a well traversing a subterranean formation adjacent to a zone in said formation which is to be plugged. The mixture is displaced into the zone and allowed to harden, thereby plugging the zone. The process is particularly applicable to sealing off water production in a gravel-packed well. A positive displacement bailer may be effectively used to deliver the mixture to the zone. The epoxy material used is immiscible with and is heavier than the fluid in the well. The epoxy material is further characterized as being essentially free of solids and having a low viscosity at downhole conditions of temperature and pressure. The hardener has an activation temperature which is lower than the downhole formation temperature.

Abstract: A mixture of an epoxy material and two hardeners is placed in a subsurface zone in which it is desired to form an impermeable zone, and the epoxy is thereafter allowed to harden. The epoxy material and hardeners are characterized inthat: (1) each hardener has a different activation temperature; (2) the amount of each hardener in the mixture is less than that required to totally react the epoxy material; (3) the epoxy material has a low viscosity at subsurface conditions of temperature and pressure; (4) the epoxy material is substantially immiscible with any fluids which are present in the subsurface area; and (5) the hardening time of the epoxy material is of short duration at subsurface conditions of temperature and pressure.

Abstract: We have found that it is possible to produce resin coated particular matter having uniform coating of resin to protect the particles against erosion or dissolution on contact with high pH fluids. The coated sand or other particles is produced by introducing the particles into a mixing device, to which is added a resin mixture comprising a urea formaldehyde resin and a furfural alcohol resin. The sand and resin mixture is mixed for sufficient time to accomplish uniform coating of the sand particle with the resin mixture. Next a foaming aqueous surfactant containing fluid is added which causes the resin-coated sand particles to be suspended in the foaming aqueous mixture. The surfactant fluid also contains acid catalyst. This mixture is allowed to set for a period of time after which the coated particles are washed and then cured at 300.degree. C. to accomplsih drying and complete the polymerization reaction.

Abstract: Disclosed are fluid and method for suspending resin coated sand in order to place the sand adjacent to a production well for the purpose of forming a permeable consolidated gravel pack. The fluid contains a viscosifying amount of hydroxyethylcellulose, sufficient fluorescent dye to increase the viscosity of the fluid, sodium chloride, and an acid forming component such as phthalic anhydride or succinic anhydride. As fluid containing the resin coated gravel particles is pumped down the injection string and positioned where it is desired to form the consolidated gravel pack, the acid forming material slowly reacts with water to form an acid, reducing the pH of the fluid, and thereby reducing the viscosity of the carrier fluid which facilitates the resin coated sand grains coming together in order to form the desired gravel pack.

Abstract: A high strength self-consolidating particle comprised of a particulate substrate, a substantially cured inner resin coating and a fusible curable outer resin coating.