Abstract: The present invention provides improved methods of cementing and cement compositions. A cement composition of the invention comprises hydraulic cement, silica hydrophobicized with a mixture of organosilicon compounds and water which upon hardening has high shear bond strength.

Abstract: Disclosed is a method to increase the bonding forces of a hydraulic cement to a subterranean pipe (such as a casing) by the addition of at least one cementitious expansive agent to increase the bulk volume of the cement plug and a latex. The method includes positioning a platform in a downhole pipe below the desired cement plug interval, positioning a plug dump bailer tool comprising a chamber for cement slurry and a valve to discharge the cement slurry on and above the platform, and discharging the cement slurry. The cement slurry includes an expansive agent and latex to increase the shear-bond between the downhole pipe and the cement plug.

Abstract: Methods and cement compositions are provided for sealing a subterranean zone penetrated by a wellbore, wherein the cement composition comprises zeolite, cementitious material, and a mixing fluid.

Abstract: Cement compositions with improved mechanical properties and associated methods are provided, which are useful in conjunction with subterranean well operations. In certain embodiments, the cement compositions comprise carbon fibers, rubber particles, a hydraulic cement material, sufficient water to form a pumpable slurry, and optionally other ingredients including a dispersant, a weighting agent, a retarding or accelerating agent, or the like.

Abstract: Cement compositions having enhanced mechanical properties and comprising microspheres and carbon fibers are provided herein. Methods are provided herein for cementing in a subterranean formation using such cement compositions. The cement compositions comprise a cement material, carbon fibers, microspheres, sufficient water to form a slurry, and optionally other ingredients including an accelerant, a retardant, a surfactant, or the like.

Abstract: The present invention provides improved well cementing methods for use in cold environment, where the circulating temperature of the cement is typically within the range of 5 to 20° C. The improved well cementing methods include forming compositions that are essentially comprised of an aqueous fluid, a hydraulic cement binder and a set-accelerating admixture comprising an alkali or alkaline earth metal nitrate and an alkali or alkaline earth metal nitrite.

Abstract: The invention concerns a cementing composition for cold zones cementing operations in an oil well or analogous, said composition comprising a aqueous fluid base, solid particles including cement particles, and a dispersing agent in solution in the aqueous fluid base, said dispersing agent having a comb-like structure composed of a graft copolymer, said graft copolymer being constituted by a backbone carrying grafted chains.

Abstract: Methods of cementing subterranean zones using cement compositions containing biogradable dispersants are provided. The methods are basically comprised of the steps of preparing a hydraulic cement, a biodegradable dispersant comprised of polyaspartic acid containing side chains formed by reacting one or more side chain chemicals with said polyaspartic acid and sufficient water to form a pumpable slurry, placing the cement composition into a zone to be cemented and allowing the cement composition to set into an impermeable solid mass therein.

Abstract: The present invention relates to stable and biodegradable foamed cement slurries, additives and methods. A foamed cement slurry of the invention comprises a hydraulic cement, sufficient water to form a slurry, sufficient gas to form a foam and a biodegradable foaming and stabilizing additive comprising a mixture of a capryl/capramido propyl betaine surfactant and a capryl/capramido propyl dimethyl amine oxide surfactant.

Abstract: The present invention relates to foamed cement slurries, additives and methods. A foamed cement slurry of the invention comprises a hydraulic cement, sufficient water to form a slurry, sufficient gas to form a foam and an environmentally benign foaming and stabilizing additive comprising a mixture of an ammonium salt of an alkyl ether sulfate surfactant, a cocoamidopropyl hydroxysultaine surfactant, a cocoamidopropyl dimethylamine oxide surfactant, sodium chloride and water.

Abstract: An improved permeable cement composition for formation of downhole sand screens. The improved composition includes an effective amount of a surfactant. Addition of the surfactant to the permeable cement composition yields at least a pumpable slurry with a minimal amount of water or brine solution.

Abstract: The present invention provides a cement composition and a process for using the cement composition to inhibit gas migration from a subterranean zone into the cement. The process comprises displacing a gelling additive, preferably comprised within a cement composition, into a well bore such that the gelling additive passes into the subterranean zone, and allowing the gelling additive to form a crosslinked gel in the subterranean zone to inhibit gas migration from the subterranean zone. The crosslinked gel acts as a barrier to gas in the subterranean zone and thereby inhibits the gas from passing into the cement and forming flow channels therein before the cement can set.

Abstract: The current invention provides a method for enhancing the formation stability of water sensitive, reactive formations penetrated by a wellbore. The method of the current invention provides an accurate evaluation of the impact of cementing fluids on water sensitive, reactive formations and provides the ability to accurately formulate cementing fluids in order to enhance the stability of such formations. When necessary, the method of the current invention additionally provides for the application of an osmotic semi-permeable membrane to the face of the formation.

Abstract: Cementing compositions for oil wells or the like comprise between 30% and 100% (by weight of cement) of rubber particles, with grain size in the 40-60 mesh range. Adding rubber particles in accordance with the invention produces a low density slurry while keeping the cement permeability low. Compositions of the invention are particularly advantageous for cementing zones subjected to extreme dynamic stresses such as perforation zones and the junctions of branches in a multi-sidetrack well.

Abstract: The present invention relates to subterranean operations, and more particularly, to settable fluids comprising vitrified shale and hydrated lime and methods of using such settable fluids in subterranean applications. In an exemplary embodiment, the settable fluids of the present invention may be used as a displacement fluid. In another exemplary embodiment, the settable fluids of the present invention may be used as a drilling fluid.

Abstract: A storable, hydraulically-active, cementitious slurry is made and used to cement within subterranean foundations for oil and gas wells. The slurry is made from a hydraulically-active cementitious material, a suspending agent, and, as a retarder, boric acid. The boric acid is present in the cementitious slurry in an amount sufficient to lower the pH of the storable cementitious slurry to at least 12.0, preferably to at least 11.0 or preferably, for reasons of longevity, to a pH of at least 9.0. Generally the amount of boric acid in the cementitious slurry is between from about 1 to about 6 percent by weight. Preferred as suspending agent are iota carrageenan as well as poly (methyl vinyl ether/maleic anhydride) decadiene copolymer. The slurry remains liquid during storage. The slurry is activated when needed for cementing and is pumped into the subterranean formation where it is allowed to set.

Abstract: Cement compositions with improved corrosion resistance, and methods of using the compositions in a subterranean formation, are provided. The cement composition comprises a high alumina cement, vitrified shale, a soluble phosphate, and water sufficient to form a slurry. Optionally, other additives may be included, such as accelerants, retardants, dispersants, and the like.

Abstract: The present invention relates to subterranean cementing operations and, more particularly, to cement composition that include improved lost circulation materials, and methods of using such cement compositions in subterranean formations. In certain exemplary embodiments, the improved lost circulation materials include inelastic particles of polyethylene, polystyrene and/or polypropylene. Optionally, the cement compositions also may include additives such as fly ash, a surfactant, a dispersant, a fluid loss control additive, a conventional lost circulation material, an generator, a retarder, a salt, a mica, fiber, a formation-conditioning agent, fumed silica, bentonite, expanding additives, microspheres, weighting materials, or a defoamer.

Abstract: The present invention provides cementing compositions for oil wells or the like comprising an hydraulic binder and reinforcing particles constituted by a flexible material of low compressibility, and with an average grain size of less than 500 microns. The compositions of the invention are of particular advantage when cementing zones which are subjected to extreme dynamic stresses, such as perforation zones and the junctions of a multi-branch lateral well. They are also highly suitable for producing plugs.

Abstract: Methods of cementing subterranean zones penetrated by well bores using cement compositions having enhanced compressive strengths are provided. A method of the invention basically comprises the steps of preparing or providing a cement composition having enhanced compressive strength upon setting comprising a hydraulic cement, sufficient water to form a slurry and a hydroxyamine compressive strength enhancing additive. Thereafter, the cement composition is placed in a subterranean zone to be cemented and allowed to set into an impermeable solid mass therein.

Abstract: An excavation fluid composition useful for enlarging a cavity in the earth includes a synthetic polymer and sodium silicate. The excavation fluid composition is formulated so as to enable the fluid in contact with unstable or sandy soils in the selected areas of the excavation to react and form silicate-based derivatives with lesser solubility, and movement and thus improve soil stability at the excavation wall.

Abstract: Cementing compositions and methods of cementing in a subterranean formation are provided. The cement composition includes a hydraulic cement, lightweight beads, and a desegregating agent for inhibiting segregation of the beads. The lightweight beads may be, for example, cenospheres, glass spheres, and ceramic spheres. The desegregating agent comprises a particulate substrate such as precipitated silica. It also comprises a polar molecule producing chemical disposed on the particulate substrate. Preferably, the polar molecule producing chemical is absorbed on the particulate substrate. The polar molecule producing chemical comprises at least one of a polar molecule producing acid such as glacial acetic acid, a salt of such an acid, and an acid anhydride. The method of cementing includes forming a pumpable slurry using the cement composition, pumping the slurry into a subterranean formation, and allowing the slurry to set.

Abstract: A method and composition is provided for sealing a subterranean zone penetrated by a well bore, wherein the sealing position comprises a mixture of gelling material, water, and cementitious material.

Abstract: A method and sealing composition is provided for sealing a subterranean zone penetrated by a well bore, wherein the sealing composition comprises a mixture of cementitious material, cross-linkable material, and sufficient water to form a slurry.

Abstract: Method of well cementing with a foamed slurry having a very low water content. When based on ordinary cement, the solid fraction of the slurry includes (by volume) 20-35% Portland cement, 35-65% particles ranging from 200 ?m to 600 ?m, and 5% to 25% of fine particles in the range 0.5 ?m to 5 ?m and the water content is less than 50% by volume. When based on micro-cement, the solid fraction includes (by volume) 50-75% micro-cement, 15-40% fine particles in the range 0.5 ?m to 5 ?m, and 0-20% particles in the rang 3 nanometers to 60 nanometers and the water content is less than 72% by volume.

Abstract: The present invention relates to methods of generating gas in and forming cement compositions that may be introduced into a subterranean zone. A method of the present invention provides a method of generating gas in a cement composition that comprises providing the cement composition comprising a hydraulic cement and water; providing an oxidizing agent; providing at least one gas generating chemical; and contacting the cement composition with the oxidizing agent and/or the gas generating chemical downstream of at least one cement pump so that a gas is generated in the cement composition downstream of at least one cement pump. Methods of foaming cement compositions are also provided.

Abstract: Methods and compositions for cementing subterranean zones penetrated by well bores are provided. The methods are basically comprised of the steps of providing a cement composition which comprises a hydraulic cement, sufficient water to form a slurry and a dispersing agent comprising a tetrapolymer formed of methacrylic acid, methacrylate, methallyl sulfonic acid and ethoxylated acrylic acid. The cement composition is placed in the subterranean zone to be cemented and allowed to set into an impermeable solid mass therein.

Abstract: Methods, compositions and fluid loss control additives for cementing in subterranean zones are disclosed. A composition comprises a hydraulic cement, sufficient water to from a slurry and a water soluble biodegradable fluid loss control additive comprising a mixture of a condensation product and hydroxyethylcellulose having a molar substitution in the range of from about 1 mole to about 2.5 moles of ethylene oxide.

Abstract: A method is given in which there is delayed release from the treatment fluid of solid chemicals that are obtained in bulk powder form. The method is used in situations in which it is difficult to encapsulate the chemical to achieve delayed release because the chemical is obtained in powdered form. The method involves delivering the powdered chemical in capsules consisting of encapsulated granulates obtained by aggregating the bulk powder under pressure to form a densified material and, optionally, then dry comminuting the densified material to produce granulates of the desired size. The treatment is hydraulic fracturing and the chemical is a breaker, or the treatment is well cementing and the chemical is a dispersing agent, fluid loss control additive, set accelerator, or extender.

Abstract: This invention relates to improved methods for completing wells in unconsolidated subterranean zones. More specifically, the present invention relates to cement compositions useful in subterranean applications, and more particularly, to permeable cement compositions and methods for forming consolidated permeable cement masses in well bores to prevent sand influx into the well bores with produced fluids. In one embodiment, the permeable cement compositions of the present invention comprise a hydraulic cement, water, and a degradable material capable of undergoing an irreversible degradation downhole.

Abstract: The present invention relates to cementing operations, and more particularly, to cement compositions comprising set retarder compositions and methods of using the cement compositions in surface and subterranean applications. In some embodiments, the present invention provides cement compositions that comprise a hydraulic cement comprising an API cement, water, and a set retarder composition, the set retarder composition comprising an acrylamide polymer derivative; and an iron compound. In other embodiments, the present invention provides cement compositions, set retarder compositions, methods of cementing, methods of retarding the set time of a cement composition, and methods of preparing a cement composition.

Abstract: The present invention provides cement compositions comprising an improved fluid loss control additive, and methods for cementing using such cement compositions. Exemplary embodiments of the cement compositions comprise a hydraulic cement, water, and a fluid loss control additive comprising an acrylamide copolymer derivative, a dispersant, and a hydratable polymer. Optionally, other additives suitable for inclusion in cement compositions may be added.

Abstract: A method for stabilizing gravel, sand, crushed stone, rock and concrete structures which have cracks by injecting a pumpable, low viscous aqueous aerated concrete with a pore volume of at least 20% by volume into the cracks at a low pressure and then increasing the pressure so that the entrained air bubbles escape and sedimentation and hydration occur.

Abstract: The storable, low-density, hydraulically-active, cementitious slurry of the invention is suitable for cementing within a subterranean formation for oil or gas wells. The low-density slurry comprises a hydraulically-active cementitious material, a set retarder, a plasticizer, glass or ceramic micro-spheres, and a strengthening agent. Further the slurry is substantially free of a suspension agent. The storable, low-density, hydraulically-active, cementitious slurry is made by adding glass or ceramic micro-spheres to a hydraulically-active cementitious material, adding a strengthening agent to the microsphere containing composition, and mixing the resulting composition with water, a set retarder, and a plasticizer to generate a slurry, wherein the set retarder is present in an amount sufficient to allow storage of the slurry.

Abstract: A lost-circulation-material includes: rubber particulates; crosslinked-copolymer particulates; cellulosic particulates; an expandable clay; a hydrogel material, and optionally a thickener. The average size of the particulates is selected so that each of the rubber particulates, crosslinked-copolymer particulates, and cellulosic particulates differ by at least a factor of 2 in diameter from one another. The components are admixed with fresh water having low salinity to form a remedial plug. In one embodiment, the copolymer particulates are pre-formed beads; the rubber particulates are finely ground butyl rubber compound; the expandable clay includes smectite; the hydrogel includes a partially hydrolyzed polyacrylamide compound; and the cellulosic particulates are wood flour. Methods of forming a slurry for plugging lost-circulation zones, and methods of treating wellbores with the slurry, are described.

Abstract: The present invention relates to subterranean operations, and more particularly, to settable fluids comprising vitrified shale and hydrated lime and methods of using such settable fluids in subterranean applications. In an exemplary embodiment, the settable fluids of the present invention may be used as a displacement fluid. In another exemplary embodiment, the settable fluids of the present invention may be used as a drilling fluid.

Abstract: A plugging fluid for plugging a subterranean formation zone surrounding a drill hole consisting of an emulsion comprising an oil phase containing an oil, an emulsifier and 2.4 to 4 kg of cement per liter of oil and an aqueous phase containing water and 12-16 g of polysaccharide per liter of water, wherein the oil to water volume ratio ranges from 20:80 to 25:75. Upon shearing, the emulsion inverts so that the rupture of the emulsion droplets releases the cement into the water phase thus providing metallic divalent ion to crosslink with the polysaccharide and forming a gel structure.

Abstract: Storable water-microsphere suspensions for use in well cements and methods of cementing well bores are provided. The storable water-microsphere suspensions are basically comprised of water, microspheres and an effective amount of a suspending agent selected from the group consisting of microfine or colloidal materials and gel forming polymers.

Abstract: The present invention provides cement compositions with improved corrosion resistance, and methods of using the compositions in a subterranean formation. The cement composition comprises a high alumina cement, vitrified shale, a soluble phosphate, and water sufficient to form a slurry. Optionally, other additives may be included, such as accelerants, retardants, dispersants, and the like.

Abstract: Biodegradable dispersants for cement slurries, well cement compositions comprising such biodegradable dispersants, and methods of using such well cement compositions are provided. The biodegradable dispersants of the present invention comprise low molecular weight starches that comprise anionic groups.

Abstract: A method and cementing composition for sealing a subterranean zone penetrated by a well bore, wherein the cementing composition comprises a mixture of cementitious material, acrylonitrile butadiene styrene (ABS), and sufficient water to form a slurry.

Abstract: Methods of cementing in wellbores using cement compositions having elasticity or high compressive strength and low permeability are provided. The cement compositions are basically comprised of particulate acid degradable glass, water, at least one water soluble polymerizable alkenoic acid monomer and a water soluble free-radical initiator.

Abstract: The present invention relates to a method to increase the bonding forces of a hydraulic cement to a subterranean pipe (such as a casing) by the addition of at least one cementitious expansive agent to increase the bulk volume of the cement plug and a latex. The method of the invention includes positioning a platform in a downhole pipe below the desired cement plug interval, positioning a plug dump bailer tool comprising a tubular storing chamber for a cement slurry and a valve to discharge the cement slurry on and above the platform and discharging a cement slurry that comprises an expansive agent and a latex in quantities enough to increase the shear-bond between the downhole pipe and the cement plug. The invention allows a significant reduction of the height of the cement plug and therefore of the number of dump-bailer operations required for placing a plug.

Abstract: A composition and method for treating oil and gas drilling fluids containing organic contaminants comprising: a solidification agent, and a cell transport agent; wherein the composition comprises enough solidification agent to enable the solidification agent to electrolytically attract the organic contaminates to the surface of the solidification agent when hydrated.

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, sodium polyphosphate, a cationic derivatized starch fluid loss control additive and water.

Abstract: The present invention provides improved methods for cementing. The methods are basically comprised of the steps of preparing a cement composition comprised of hydraulic cement, water, gas, surfactants, a cement early strength accelerator and a mildly set retarding cement dispersing agent, placing the cement composition in the annulus between the casing string and the well bore and allowing the cement composition to set into a hard impermeable mass. The cement composition used can alternatively comprise hydraulic cement, a water reducing additive, a dispersing additive, a set accelerating additive and water. Also, the cement composition can be made environmentally benign by using water reducing and dispersing additives, set retarding additives, and compressive strength and set accelerating additives which are environmentally degradable.

Abstract: The current invention provides improved methods and compositions for completing a well bore. In one aspect, the current invention provides a process for preparing a foamed well composition. The process utilizes air to foam the composition after the air has been treated to lower the oxygen content below that concentration necessary to support combustion. Additionally, the current invention provides a process for completing and/or treating a well bore using a foamed composition wherein the foam is generated with reduced oxygen content air. Finally, a preferred embodiment of the invention provides a foamed cement composition wherein the gaseous portion of the composition is air having a reduced oxygen content.

Abstract: Methods of cementing in subterranean formations, cement compositions, and methods for making the compositions are provided. A cement slurry is passed into a subterranean formation, and a swelling agent is passed into the subterranean formation to reduce an amount of water flowing into the cement slurry. The swelling agent may be combined with a carrier fluid before being displaced into the subterranean formation. Alternatively, the swelling agent may be pre-mixed with the cement slurry to form a new cement composition, followed by displacing the cement composition into the subterranean formation. The swelling agent is present in an amount effective to, upon absorption of water and swelling to form a gel mass, substantially block the flow path of the water into the cement composition or reduce losses to low pore pressure intervals, thereby preventing the integrity of the cement composition from being compromised or lost to voidage, fractures, fissures, etc.

Abstract: Cementing compositions and methods of cementing in a subterranean formation are provided. The cement composition includes a hydraulic cement, lightweight beads, and a desegregating agent for inhibiting segregation of the beads. The lightweight beads may be, for example, cenospheres, glass spheres, and ceramic spheres. The desegregating agent comprises a particulate substrate such as precipitated silica. It also comprises a polar molecule producing chemical disposed on the particulate substrate. Preferably, the polar molecule producing chemical is absorbed on the particulate substrate. The polar molecule producing chemical comprises at least one of a polar molecule producing acid such as glacial acetic acid, a salt of such an acid, and an acid anhydride. The method of cementing includes forming a pumpable slurry using the cement composition, pumping the slurry into a subterranean formation, and allowing the slurry to set.

Abstract: The present invention provides cement compositions with improved mechanical properties and methods of using same, which are useful in conjunction with subterranean well operations. The cement compositions comprise carbon fibers, rubber particles, a hydraulic cement material, sufficient water to form a pumpable slurry, and optionally other ingredients including a dispersant, a weighting agent, a retarding or accelerating agent, or the like.