Abstract: A method for strengthening a subterranean formation by injecting an aqueous gellable composition containing a cross-inkable polymer into the subterranean formation through a wellbore to increase the strength of the subterranean formation while retaining the ability of the subterranean formation to produce fluids.

Abstract: A wellbore service fluid comprising polymers having cross-linking groups capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents is described, and related methods, particularly applicable to water control operations.

Abstract: The present invention provides light weight high temperature well cement compositions and methods. The compositions are basically comprised of calcium aluminate, ASTM class F fly ash and water.

Abstract: The invention provides a method and fluid for drilling or servicing a well in a subterranean formation, particularly containing lost circulation zones or depleted, low pressure reservoirs. A method of decreasing the density of the fluid circulated in a borehole, decreasing the invasion of fluid into formations contacted by the fluid, or decreasing the lost circulation potential of the fluid is provided by using as the fluid an aqueous liquid having dispersed therein a polymer which increases the low shear rate viscosity of the fluid to the extent that the shear thinning index of the fluid is at least about 10, a surfactant, and aphrons, wherein the aphrons are preferably generated by the turbulence and pressure drop as the fluid exits the drill bit in the vicinity of the formation, the fluid having a low shear rate viscosity of at least 10,000 centipoise.

Abstract: The present invention relates to methods of reducing water produced with hydrocarbons from subterranean formations penetrated by well bores. The methods basically comprise the steps of coating a particulate solid material with an organic polymer which reacts with water and swells when contacted therewith whereby the flow of water through a pack of the resulting polymer coated particulate solid material is reduced or prevented, and thereafter, placing a pack of the polymer coated particulate solid material in or adjacent to the formation whereby water and hydrocarbons produced from the formation are caused to flow through the pack.

Abstract: The present invention provides improved compositions and methods for sealing pipe in well bores. The compositions are basically comprised of an aqueous rubber latex, a rubber latex activator for causing the latex to harden, an organosilane and a filler.

Abstract: The disclosed invention provides a method for recovering hydrocarbons from a subterranean formation by injecting an emulsion, comprising oil and water, into the formation. More specifically, the emulsion is stabilized using undissolved solid particles, which are preferably at least partially oleophilic. The solids-stabilized emulsion may be used either as a drive fluid for displacing hydrocarbons from the formation or to produce a barrier for diverting flow of fluids in the formation. Such solid particles may be either formation solid particles (i.e., indigenous to the formation) or nonformation solid particles (i.e., obtained from outside the formation). Nonformation solid particles may either be naturally occurring or synthetic. Some preferred solids include clays, quartz, feldspar, gypsum, coal dust, asphaltenes, and polymers.

Abstract: The present invention provides methods and compositions for sealing subterranean zones. The methods of the invention basically comprise the steps of preparing a sealing composition comprised of an aqueous alkali metal silicate solution, a gelling agent and a delayed acid activator for causing the composition to set into a rigid mass, placing the sealing composition in said subterranean zone and allowing the sealing composition to set into a rigid sealing mass therein.

Abstract: A method for improving the a real sweep efficiency of a waterflood process is described. Reservoir heterogeneity results in the waterflood being diverted to the thief zones, bypassing much of the in-place hydrocarbon fluids. Existing remedial options are sensitive to water chemistry and temperature and are mostly effective near the wellbore. The unique advantages of this process is that it is insensitive to the water phase, in-depth in its placement, and can be triggered by pressure change which no other existing process offers.

Abstract: Methods and compositions for preventing high density well completion fluid loss are provided. The methods basically comprise the steps of preparing a high density cross-linked aqueous gelled composition having the rigidity required to resist entry into a permeable subterranean formation penetrated by a well bore, placing the high density cross-linked aqueous gelled composition in the portion of the well bore within the permeable subterranean formation and placing a high density completion fluid in the well bore behind the high density cross-linked gelled composition.

Abstract: A process and a material for use in sealing casing lining in a borehole is taught. The process includes the placement of a bitumen sealant material in a position between the casing tube and the wall of the borehole to be maintained in this annulus by means of a retaining devise such as an external casing packer or with the placement of a retainer made of cement grout and situated at the lower end of the casing tube. The bitumen sealant material prevents the passage of fluids vertically through the borehole. The sealant material remains viscous over time and can flow to fill voids which may occur in the rock formations adjacent to the borehole, or in the steel casing of the casing tube. To improve the sealing capabilities of the bitumen material a measured amount of fine grain weight material can be added to the bitumen to increase the density of the sealant material and thereby increase the hydrostatic pressure that the column of bitumen sealant will exert on the bottom and the walls of the borehole.

Abstract: A degradable ball sealer for use in the oil and gas industry is disclosed. The ball seat comprises a particular composition of matter and injection molding technique that provides a ball seal which will dissolve in stimulation or wellbore fluids after stimulation operations are complete. In use, the surface of the ball sealer softens slightly assuring a solid seal between the ball the and the casing perforation. The composition when dissolved into wellbore fluids does not pose a hazard and disperses well in aqueous based wellbore fluids. The same composition, made into a larger ball, may be used as a tubing sealer for pressure testing.

Abstract: Well completion methods using an aqueous polymer composition such as rubber latex in a subterranean formation containing a salt zone. The composition is used to form a protective layer on the salt zone. The layer is substantially impermeable to fluids and prevents them from contacting the salt zone and creating a washed-out area therein. Further, the layer enables a freshwater cement slurry to be used in the well completion operations through the salt zone.

Abstract: A grouting system for well casings (26) uses a grout wrap (10) including first (12) and second (14) flexible sheets with a layer (16) of flexible, hydrophilic grout material therebetween that expands upon absorption of water. In the preferred embodiment, each well casing section (30a,b) is enclosed by the preferred grout wrap (10) before placement in the well hole (28). After placement, the grout material is exposed to water for absorption so that the grout material expands and seals the casing.

Abstract: A process is provided for constructing a fluid impermeable subterranean barrier wall in a permeable earthen material at an earthen surface. The process is initiated by excavating an earthen pit in the permeable earthen material. A gelable slurry is prepared including unconsolidated solids, an aqueous solvent, a crosslinkable polymer, and a polymer crosslinking agent. The unconsolidated solids have a bulk component consisting of a soil or a clay. The unconsolidated solids can also include a number of additive agents which enhance the performance of the gelable slurry, such as density control agents, mixing agents, permeability reduction agents, filtration control agents and strength loss reduction agents. The gelable slurry is placed in the earthen pit and gelled to substantial maturity. The resulting gel binds the unconsolidated solids present in the earthen pit to convert the gelable slurry to a gelled continuum of consolidated solids, which forms the fluid impermeable barrier wall in the earthen pit.

Abstract: The disclosed invention provides a method for recovering hydrocarbons from a subterranean formation by injecting an emulsion, comprising oil and water, into the formation. More specifically, the emulsion is stabilized using undissolved solid particles, which are preferably at least partially oleophilic. The solids-stabilized emulsion may be used either as a drive fluid for displacing hydrocarbons from the formation or to produce a barrier for diverting flow of fluids in the formation. Such solid particles may be either formation solid particles (i.e., indigenous to the formation) or nonformation solid particles (i.e., obtained from outside the formation). Nonformation solid particles may either be naturally occurring or synthetic. Some preferred solids include clays, quartz, feldspar, gypsum, coal dust, asphaltenes, and polymers.

Abstract: The present invention provides improved methods of sealing a subterranean zone to remedy the uncontrolled flow of fluids into and out of the zone. The methods basically comprise preparing a sealing composition and placing the composition into the zone to be sealed. The placement of the composition is controlled in a manner whereby portions of the sealing composition are continuously converted to sealing masses which are successively diverted into permeable portions of the zone until all of the permeable portions are sealed.

Abstract: The present invention provides light weight high temperature well cement compositions and methods. The compositions are basically comprised of calcium phosphate cement, water, a foaming agent, a foam stabilizer and a gas present in an amount sufficient to form a foam having a density in the range from about 11.5 to about 15 pounds per gallon.

Abstract: The present invention relates to improved foamed well cement compositions, additives and methods. The additives, which foam and stabilize a cement slurry containing freshwater or saltwater, are basically comprised of an aqueous solution of an alpha-olefinic sulfonate surfactant and a betaine surfactant.

Abstract: There is provided an additive for and a method of using the additive to treat a clay-containing earthen formation, such as a subterranean formation, to substantially reduce formation damage caused by contact of the formation with an aqueous liquid foreign to the formation. The additive, which is employed in a water solution, is comprised of a chloride-free, quaternary ammonium compound which can be used without adverse affect upon animal, soil and water resources due to the chloride-free and substantial organic nature thereof. It thus biodegrades to environmentally acceptable end products.

Abstract: The present invention provides set retarding additives, set retarded hydraulic cement compositions and methods of using the set retarded cement compositions for cementing subterranean zones in wells. A preferred set retarding additive comprises an alkanolamine salt produced by the reaction of a hydroxy carboxy acid, such as tartaric acid, gluconic acid or glucoheptonic acid, with an alkanolamine, such as monoethanolamine, diethanolamine or triethanolamine.

Abstract: The present invention relates to improved methods and compositions for performing well completion or remedial procedures in subterranean zones having temperatures below about 70.degree. F. The methods basically comprise the steps of introducing into the zone an aqueous solution of a polymerizable monomer, a polymerization initiator and an oxygen scavenger comprised of stannous chloride. Thereafter, the polymerizable monomer is allowed to polymerize in the zone. The stannous chloride scavenges oxygen without generating free radicals and causing premature polymerization.

Abstract: Ground peanut hulls in the range of -150 to 250 standard size mesh are mixed with a viscosifier and added to a fluid for circulation in a borehole during drilling, completion and workover operations. Below 250 standard sieve mesh the ground peanut hulls are distributed in a range down to 700 standard sieve mesh, with some of the ground peanut hulls having a size less than 700 standard sieve mesh.

Abstract: A gelling composition comprises a multivalent metal compound-crosslinkable polymer such as a carboxylate-containing polymer, a multivalent metal compound such as a zirconium compound, a liquid, and a pH-lowering agent such as carbon dioxide wherein the composition is prepared by combining the polymer and multivalent metal compound to form a mixture and, thereafter, introducing carbon dioxide to the mixture. A process for treating a subterranean formation can comprise the steps of: (1) combining a polymer with a multivalent compound to form a mixture; (2) introducing the another mixture into a subterranean formation; and (3) introducing carbon dioxide into the mixture.

Abstract: Compositions and methods for modifying the permeability of subterranean formations are shown. The compositions and methods generally comprise forming a dispersion of water swellable crosslinked polymer particles, adding the dispersion to a carrier fluid to form a treatment fluid, and injecting the treatment fluid into the subterranean formation. The particles are made by polymer emulsion or microemulsion processes, resulting in particles that are much smaller in size than that of the formation pore strictures. Upon injection, the particles become trapped in the formation, and upon flowback of water, the particles swell in size and adsorb onto the formation, forming a film and restricting further fluid flow.

Abstract: The invention herein provides a method for the time delayed precipitation of a solid phase of metal from a low pH, metal salt solution comprising adding to the metal solution a substrate, such as an amide, and an enzyme, such as an amidase, which will react with the substrate, which causes a rise in pH upon the reaction of the substrate with the enzyme. The rise in pH causes the metal to precipitate from solution. The precipitated metal is useful for emplacing metal hydroxides for providing sorptive material useful for removing contamination from groundwater.

Abstract: In a drilling well, well completion, or well workover, the permeability of the walls is controlled by adding a predetermined amount of at least one hydrophobically modified guar gum derivative, e.g., a hydrophobically modified hydroxypropyl guar (HMPG), so as to reduce the amount of filtrate lost through the walls. The fluid may also include viscosifiers such as polymers or reactive clay.

Abstract: Polymer enhanced foam fluid is utilized for completion, workover, and kill operations in wells penetrating subterranean formations. The foam is formed by appropriately adding a gas to an aqueous solution of a substantially noncrosslinked water soluble polymer and a surfactant. The solution and the foam are substantially free of crosslinking agents. The foam may be generated at the surface or in a wellbore.

Abstract: The present invention relates to methods and compositions for reducing the production of water from water and oil producing subterranean formations. The methods basically comprise the introduction of an aqueous polymer composition into the water producing zones of the formation which cross-links after being placed therein. The compositions of the invention are comprised of a heavy brine and a graft copolymer of a hydrophilic polymer and a phosphonate.

Abstract: The present invention provides a method of controlling fluid loss to a permeable formation penetrated by a wellbore. A novel fluid loss agent is prepared by forming a crosslinked polymer gel which then is sheared to break the gel into discrete particles of a particular size range. A slurry then is formed of the particles by dispersing the particles in an aqueous fluid having a density similar to that of the gel particles. The slurry then is introduced into contact with the permeable formation and a filter cake of the particles is formed upon contact with the formation and loss of the slurrying fluid to the formation. The filter cake provides further fluid loss control to the permeable formation.

Abstract: The present invention provides set retarding additives, set retarded hydraulic cement compositions and methods of using the set retarded cement compositions for cementing subterranean zones in wells. A preferred set retarding additive comprises an alkanolamine salt produced by the reaction of a hydroxy carboxy acid, such as tartaric acid, gluconic acid or glucoheptonic acid, with an alkanolamine, such as monoethanolamine, diethanolamine or triethanolamine.

Abstract: The present invention provides well cementing methods and compositions for use in cold environments which are particularly suitable for cementing conductor strings in deep water offshore wells. The cement compositions are basically comprised of a relatively coarse particulate hydraulic cement mixed with an ultra fine particulate hydraulic cement, sufficient water to form a pumpable slurry and a fluid loss control additive.

Abstract: The present invention provides improved cementitious compositions which can include drilling fluid as a component thereof and methods of cementing wells utilizing such compositions. The compositions are basically comprised of a cementitious material, water, a hardenable resinous material and optionally, drilling fluid in an amount up to about 70% by volume of the cementitious material in the composition.

Abstract: Borated starch compositions useful for controlling the rate of crosslinking of hydratable polymers in aqueous media for use in drilling fluids.

Abstract: The permeability of a subterranean reservoir can be more easily controlled by first injecting a crosslinking agent solution and then subsequently injecting a scleroglucan solution to thereby form, in situ, crosslinked scleroglucan gel. This reverse order of injection allows for a more homogeneous gel propagation without substantial risk of plugging.

Abstract: High temperature blocking gel is shown for temporary workover operations. The blocking gel is prepared by blending a guar or derivatized guar polymer with an aqueous fluid. The mixing method employed mixes and pumps the guar polymer essentially unhydrated. The resulting lower viscosity minimizes friction pressure during placement.

Abstract: The present invention provides set retarding additives, set retarded hydraulic cement compositions including such additives and methods of using the cement compositions for cementing zones in wells. The set retarding additives are copolymers or terpolymers containing monomer units formed from one of maleic acid, itaconic acid, fumaric acid, citraconic acid and mesaconic acid along with other monomer units.

Abstract: A method for retarding the effect of water coning during the production of oil from a subterranean formation is described. The retarding occurs by injecting into the subterranean formation, at or below the oil/water interface, a polymer solution having a viscosity at least twice that of the connate water to form a zone of high viscosity about the wellbore during the oil production.

Abstract: A flexible grout composition and method of disposing the composition in position, in contact with an earthen formation, such as a coating on a trench wall, or within a bore hole, for example to cement a conduit within the bore hole to prevent fluid loss, for sealing and grouting well casings, plugging abandoned wells, and waterproofing earthen structures, particularly in environments where the grout composition is in contact with contaminated water. The flexible grout composition includes a water-swellable clay, such as sodium bentonite; an optional solid particulate filler, such as an essentially nonswellable bentonite clay, such as calcium bentonite, herein defined as a bentonite clay having calcium as the predominant exchangeable cation; a water-soluble polymer; and an optional dispersing agent, such as sodium acid pyrophosphate (SAPP).

Abstract: The production of excessive water in oil and gas wells and other subterranean formations is reduced by introducing a hydrocarbon fluid containing dispersed superabsorbing particles formed using invert emulsion polymerization techniques wherein the superabsorbing particles are formed from hydratable polymers which are cross-linked so that they are insoluble in water. By introducing these superabsorbing particles into fluid passages of the formation, the water producing zones can be selectively blocked off by allowing the superabsorbing particles to swell with the absorption of water within the aqueous fluid containing fluid passages, while the superabsorbing particles remain small and unswollen in the hydrocarbon conducting fluid passages. Thus, the ability of fluids to flow through the aqueous fluid containing fluid passages is selectively reduced resulting in the reduced production of aqueous fluids while maintaining production of hydrocarbons.

Abstract: The present invention provides a method of controlling fluid loss to a permeable formation penetrated by a wellbore. A novel fluid loss agent is prepared by forming a crosslinked polymer gel which then is sheared to break the gel into discrete particles. A slurry then is formed of the particles by dispersing the particles in an aqueous fluid having a density similar to that of the gel particles. The slurry then is introduced into contact with the permeable formation and a filter cake of the particles is formed upon contact with the formation and loss of the slurrying fluid to the formation. The filter cake provides further fluid loss control to the permeable formation.

Abstract: Hydraulic fractures which extend between a hydrocarbon fluid producing zone of an earth formation and a water-producing zone are sealed with respect to the water-producing zone by simultaneously injecting a non-sealing fluid such as crude oil, diesel fuel or brine into the portion of the fracture extending within the hydrocarbon producing zone and injecting a settable gel composition such as a polyacrylamide polymer cross-linked with inorganic transition metals into the portion of the fracture extending within the water-producing zone. The flow rates of the simultaneously pumped fluids are controlled in accordance with the ratio of the respective fracture heights and the viscosity and density of the respective sealing and non-sealing fluids. One fluid is typically pumped through the well annulus while the other fluid is pumped through a tubing string which is sealed from the annulus by a conventional packer disposed at the interface between the hydrocarbon and water-bearing zones.

Abstract: A process for treating a subterranean formation comprises adding a crosslinking agent intermittently to a stream of gellable polymer wherein the gellable polymer forms a gel in the formation, in the presence of the crosslinking agent.

Abstract: A process for plugging an underground strata to prevent coning, i.e. the intrusion into an oil production stream of gas located above an oil producing formation and/or water located below the formation from which the oil is being produced, by introducing a polymer or a surfactant together with a cosolvent into into a gaseous stream, e.g. carbon dioxide, in such ratio as to make the mixture just homogeneous when injected through the appropriate perforations into the zones above and below the oil bearing strata and yet subject to destabilization thereafter, either through some exiting feature of the reservoir such as temperature or the presence of water, or through some externally implemented event, such as a sudden lowering of the pressure in the vicinity of the well bore, to cause the polymer or surfactant to come out of solution and aid in plugging the zones through which vertical movement of gas and water, i.e. coning, had been taking place.

Abstract: Cement set retarding additives, set retarded hydraulic cement compositions and methods of using the cement compositions for cementing zones in wells are provided. The set retarding additives are copolymers containing monomer units formed from a first monomer of acrylic acid or methacrylic acid and a second monomer of acrylamide or a derivative of acrylamide.

Abstract: N-phosphonomethyl iminodiacetic acid may be used as an additive to retard the setting time of Portland cement.

Abstract: A method of recovering hydrocarbons from an underground reservoir with a cyclic injection/production process, wherein after one or more injection and production cycles, a second recovery fluid is injected into the formation comprising a cosolvent, a solute, preferably polydimethylsiloxane, and the primary recovery fluid such as carbon dioxide, said second fluid composition designed for solute to drop out of solution in the formation during the later soaking and production phases.

Abstract: Improved cement compositions and methods of using such compositions in carrying out construction and remedial operations in oil and gas wells at high temperatures are provided. The compositions are basically comprised of hydraulic cement, sufficient water to form a pumpable slurry, and a dispersing and stabilizing additive comprised of an ethoxylated alkali metal salt of an alkyl polyether sulfonate.

Abstract: Fibers are added to a gelation solution and the mixture is pumped to a subterranean injection site where it gels in place. The gelation solution is preferably comprised of partially hydrolyzed polyacrylamide polymer and a crosslinking agent, while the fibers are those which do not interfere with the gelation process and can provide adequate reinforcement while not adversely affecting the ability of the solution to be pumped and injected. Glass fibers and cellulosic fibers are specifically disclosed as preferable reinforcing fibers.

Abstract: A soil treatment process is provided utilizing a polymer enhanced foam to block the flow of a migratory fluid in a soil. Placement of the polymer enhanced foam in a desired treatment region of the soil produces a seal that substantially eliminates the permeability of the treatment region to the migratory fluid and prevents migration of fluid across the region. In each of its numerous embodiments, the process can be employed as either a remedial or a preventative treatment.