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: An improved method of cementing casing in a deep water offshore formation penetrated by a well bore comprising the steps of preparing a foamed cement composition comprised of calcium aluminate cement, a set accelerating additive, a thickening time increasing additive, water, a gas, and a mixture of foam forming and foam stabilizing surfactants; placing the cement composition in the annulus between the casing and well bore; and allowing the cement composition to set into a hard impermeable mass therein.

Abstract: The invention pertains to a method for producing rapid setting cement and to the compositions produced therefrom. The setting time of hydraulic cement compositions comprising Portland cement and fly ash can be accelerated by controlling the pH of an activator slurry used in the composition. The pH of the activator slurry is controlled by non-stoichiometrically balancing the accelerating salts therein such that the activator slurry is alkaline, or having a pH greater than 7. The slurry activator of the present invention generally includes a base component, an acid component, and water. The base component can include any basic alkali and alkaline earth metal hydroxide, or a salt of the acid component. The acid component may include a hydroxycarboxylic acid, preferably citric acid. Mortar and concrete compositions can be prepared with this hydraulic cement wherein the compositions can achieve high strengths in a short time.

Abstract: In some embodiments, alternate sources of aluminum or calcium are provided in various ways including the desired compounds. The further object of the present invention contemplate in situ creation of the compound in interest in fresh concrete and as a slurry which can be employed in remediation of existing concrete structures. A method of resisting corrosion in concrete containing metal elements is provided. It includes introducing into fresh concrete, containing metal elements, at least one compound capable of sequestering chloride ions. The method may also involve employing a compound which is capable of establishing a corrosion resistant oxide layer on the metal reinforcing elements. The invention also includes certain compounds which may be employed in the method as well as concrete structures containing the compounds.

Abstract: The subject matter of the invention is a new additive for mineral binders comprising a composition containing at least one product of internal dehydration of a hydrogenated sugar which can especially be a dehydrated hexitol such as isosorbide, isomannide, sorbitan or mannitan and which can be introduced at a rate of between roughly 0.001 and 5% (dry/dry) within any mineral binder, said additive being advantageously used as an accelerator for setting and/or hardening and/or as an agent for improving the mechanical properties of the mineral binder. It has a remarkable efficiency, including at low temperatures.

Abstract: Powdered material, the binder phase of which mainly consists of a cement-based system, which powdered material has the capacity following saturation with a liquid reacting with the binder phase to hydrate to a chemically bonded ceramic material, preferably for dental purposes. According to the invention the powdered material has a composition and/or structure suitable for giving the ceramic material translucence in the hydrated state. The invention also relates to the ceramic material produced by hydration of the powdered material.

Abstract: Powdered material, the binder phase of which mainly consists of a cement-based system, which powdered material has the capacity following saturation with a liquid reacting with the binder phase to hydrate to a radiopaque and chemically bonded ceramic material. According to the invention, said binder phase mainly consists of CaO.Al2O3 (ss) and/or 3CaO.Al2O3 (ss). The material also contains one or more heavy atom types with a density over 5 g/cm3. The invention also relates to a method for manufacturing the powdered material and the chemically bonded ceramic material formed from the powdered material, in which said binder phase has a mol ratio Al2O3.3H2O (ss) to 3CaO.Al2O3.6H2O (ss) of a maximum of 2:1.

Abstract: Exemplary liquid cement additive compositions have high solids loading which includes alkali or alkaline earth metal salts and other cement additive components. The liquid carrier is preferably aqueous in nature, although non-aqueous carriers are possible, and the carrier is modified using a viscosity modifying agent and dispersant to help load salt and other solids in high level amounts. Thus, methods for making the liquid cement additive compositions are also disclosed.

Abstract: Herein is disclosed an admixture, for concrete, gypsum panels, and other cementitious products, derived from fermentation still bottoms. The admixture typically comprises protein, glycerol, and lactate, as well as smaller amounts of other alcohols, sugars, and other organic acids. The admixture may be present as a solution (typically comprising about 30-50 wt % solids) or as a dry mixture. The admixture allows increased flow and reduced water use in concrete and gypsum slurries used in gypsum panel production. Concrete, cement, and gypsum premixes, ready-mixes, and poured structures are disclosed.

Abstract: The present invention provides improved foamed well cement slurries, additives and methods. The foamed well cement slurries are basically comprised of a hydraulic cement, sufficient water to form a pumpable slurry, sufficient gas to form a foam and an effective amount of an additive for foaming the slurry comprised of hydrolyzed keratin.

Abstract: The present invention is related to a calcium tartrate plaster retarding composition, characterised in that it has a mean particle size lower than 30 &mgr;m. The present invention is also related to the plaster comprising said composition and to the preparation process of said composition.

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 white pozzolan derived from by-products of manufacturing vitreous low alkali, low iron glass fibers, and to the method for producing the white pozzolan. The invention relates as well to cement compositions based on the white pozzolan, such as white and pigmented blended pozzolanic cements of high durability for use in applications such as white or colored architectural concrete, building materials, and manufactured cementitious products. The white pozzolan also functions as a high performance pozzolan with grey cement.

Abstract: The present invention relates to an inorganic cohesion agent for self-compacting cement pastes consisting of a co-precipitated SiO2/CaCO3 mixture.

Abstract: Exemplary liquid cement additive compositions have high solids loading which includes alkali or alkaline earth metal salts and other cement additive components. The liquid carrier is preferably aqueous in nature, although nonaqueous carriers are possible, and the carrier is modified using a viscosity modifying agent and dispersant to help load salt and other solids in high level amounts. Thus, methods for making the liquid cement additive compositions are also disclosed.

Abstract: Additives for the building sector obtained from plant by-products or waste suspended through wet-grinding of aggregates thereof are disclosed. Such additives may be chosen among silica fume, fly ashes, heavy ashes, slags or stone sludge, in form of pellets, sludge or blocks. The invention also relates to a process for preparing the additives in which the plant by-products and/or waste are wet-ground and suspended by means of a microballs mill.

Abstract: Cement comprising barite, a process for preparing such cement, and methods of cementing in a subterranean formation or well bore using such cement are provided. The cement is prepared by introducing coarse barite to the cement, the course barite comprising particles having a particle size primarily greater than about 125 microns. Preferably, 90 percent of the barite particles is greater than about 125 microns in size. The presence of the coarse barite in the cement causes the cement to have a relatively low viscosity. Introducing the barite to the cement also increases the density of the cement, thus rendering the cement capable of controlling high hydrostatic pressures in a well bore.

Abstract: The invention provides an antibacterial agent for concrete comprising a silver compound, a copper compound and an ion-retaining compound; a concrete composition comprising the antibacterial agent; and a concrete product produced from the concrete composition. The concrete composition containing the antibacterial agent and the concrete product produced using the concrete composition show excellent antibacterial effect against causative bacteria of the corrosion of concrete such as sulfur reducing bacteria, sulfur oxidizing bacteria and carboxylic acid-producing bacteria, in particular, in sewage treatment plants.

Abstract: The current invention provides 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: A method for promoting cement or concrete set on demand for concrete that has been chemically retarded by adding carbon fiber to the concrete, which enables it to become electrically conductive, sodium tartrate retardant, and copper sulfate which forms a copper tartrate complex in alkaline concrete mixes. Using electricity, the concrete mix anodically converts the retarding tartrate to an insoluble polyester polymer. The carbon fibers act as a continuous anode surface with a counter electrode wire embedded in the mix. Upon energizing, the retarding effect of tartrate is defeated by formation of the polyester polymer through condensation esterification thereby allowing the normal set to proceed unimpeded.

Abstract: The invention provides an antibacterial agent for concrete comprising a silver compound, a copper compound and an ion-retaining compound; a concrete composition comprising the antibacterial agent; and a concrete product produced from the concrete composition.

Abstract: The invention pertains to a method of delaying the set time of cement and to compositions produced therefrom. The set time of hydraulic cement mixtures of fly ash pozzolans, specifically Class C and Class F, and Portland cement can be delayed by controlling the pH of a retarder slurry that is mixed with the dry components of the composition. The pH of the retarder slurry is controlled by balancing the salts therein such that the retarder slurry is acidic, or having a pH less than 7. The slurry activator of the present invention generally includes a pH balancing agent, an acid component, and water. The pH balancing agent can include any basic alkali and alkaline earth metal hydroxide, or a salt of the acid component. The acid component may include a hydroxycarboxylic acid, preferably citric acid. Slower setting mortar and concrete compositions having high strength can be prepared with this hydraulic cement.

Abstract: Natural fiber-containing cement compositions for cementing wellbores in high stress and high temperature environments. The cement compositions may contain natural mineral fiber materials such as wollastonite in an amount of greater than about 10% and in an amount selected to be effective to achieve ratios of flexural strength to compressive strength of cured cement that are greater than about 0.35 at downhole temperatures of greater than about 180° F.

Abstract: An accelerating admixture for sprayed concrete comprises: (a) the reaction product of aluminium hydroxide with an organic acid; (b) aluminium sulphate; and (c) at least one alkanolamine. Concrete to which accelerator has been added sets rapidly.

Abstract: A method and cementing composition is provided 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: A slurry for hydrocarbon production and water injection well cementing, and procedures to cement wells using such slurry are provided. The slurry contains at least cement and water, and at least an amount of fibers in a ratio of 0.1 to 0.8% in weight with respect to cement weight, where the fibers may in general be of polypropylene, polystyrene, carbon, alkali-resistant glass, cellulose or polymers. The slurry may also comprise other additives, such as dispersants, fluid loss agents, accelerators and retarders, chemical extenders and latex, among others. Procedures to cement hydrocarbon production wells or water injection wells are also described, where the cement slurry is prepared incorporating fibers into the slurry separately or mixing them with the remaining dry components before adding water.

Abstract: The present invention relates to an additive which is added in order to reinforce cement. The additive comprises chlorides of alkali metals, alkaline earth metals and/or transition metals and oxides selected from the group consisting of alkali metal and alkaline earth metal oxides, aluminum oxide, silica, apatite and/or zeolites and comprises, in particular, a combination of sodium chloride, ammonium chloride, aluminium chloride, potassium chloride, calcium chloride, magnesium chloride, magnesium oxide, magnesium sulphate, sodium carbonate, silica, apatite and/or zeolites. Additives of this type can be used, inter alia, to stabilize/modify cement; consolidate sand and/or soil, such as when building roads, dykes, tunnels, foundations and the like, immobilize pollutants, during the injection of cement compositions, such as grouting, and for the production of concrete.

Abstract: Gypsum plaster compositions with improved adhesion to plastic surfaces and metal surfaces comprise from 10 to 90% by weight of gypsum plaster, based on the total weight of the composition, and also, where appropriate, other additives, and a combination of: a) one or more water-redispersible polymer powders based on one or more vinyl ester, (meth)acrylate, vinylaromatic, olefin, 1,3-diene, or vinyl halides monomers, and optionally other monomers copolymerizable therewith; and b) one or more alkali metal and/or alkaline earth metal salts of short-chain fatty acids having from 1 to 4 carbon atoms in the hydrocarbon skeleton and from 1 to 4 carboxy groups, and which contain no OH groups.

Abstract: An alkali-free accelerator for sprayed concrete is prepared by dissolving aluminium sulphate and amorphous aluminium hydroxide in water which optionally contains one amine, and optionally adding at least one stabiliser, selected from hydroxycarboxylic acid and phosphoric acids and non-alkaline salts thereof, and at least one defoaming agent.

Abstract: The present invention provides methods, lightweight well cement compositions and additives for the well cement compositions. The methods of the invention for sealing pipe in a well bore penetrating a zone or formation which readily fractures at low hydrostatic pressure is basically comprised of the steps of providing a lightweight cement composition comprised of a hydraulic cement, water and an additive comprising an aqueous suspension of microspheres containing a water swellable clay suspending agent, placing the cement composition in the annulus between the pipe and the well bore and allowing the cement composition to set.

Abstract: The present invention is directed at a synthetic lightweight aggregate composition comprising fly ash and a mixture of two or more polymer components. More specifically, the present invention is also directed at a lightweight concrete which cures to a hardened cementious composite comprising Portland cement, water in a weight ratio of between about 0.2 and 0.7 of the water to the Portland cement, synthetic lightweight aggregate in a weight ratio of between about 0.1 and 0.5 of the synthetic lightweight aggregate to the cement, wherein the synthetic lightweight aggregate comprises fly ash and two or more polymer components.

Abstract: It has been found that a large variety of solid chemicals available in a bulk powder form could be added to subterranean treatment fluids with delayed release when said chemicals are delivered as capsules consisting of encapsulated granulates obtained by aggregating the bulk powder under pressure to form a densified material and optionally, dry comminuting said densified material to produce granulates at the desired size. The invention is particularly useful for delivering new types of breaking agents for stimulation fluids or additives for wellbore cementing.

Abstract: The present invention relates to settable compositions for general purpose concrete construction containing Class-F fly ash, Class-C fly ash or slag, and potassium chloride (KCl) as a substantial replacement for Portland cement conventionally used in such compositions. The potassium chloride is an additive for improved high early strength and accelerated setting times, thereby allowing the concrete structure to be put into service sooner, reducing labor cost, and allowing precast concrete and concrete masonry manufacturers to achieve rapid form and mold turnover.

Abstract: Substantially hydrated cementitious particulates useful for delivering admixtures and additives into adhesives, coatings, paints, and other matrix compositions such as cement, concrete, masonry, mortar, fireproofing, shotcrete, and others. Preferred embodiments include intermixing at least one admixture, water, and hydratable cementitious binder to provide a substantially hydrated hardened mass and comminuting the hardened mass into particulates. Alternatively, or in addition, one or more admixtures may be coated onto the external surface area of the particulates, which are microscopically granulosic, to provide accurate and high level loading.

Abstract: The surface deactivating composition for concrete or mortar comprising a retardant, water and if desired a rheology modifying agent of the HASE type (emulsion, soluble in alkali, of a polymer with hydrophobic modification), characterized in that the retardant is a carboxylic acid and in that the concentration of HASE is greater than or equal to 0.5% by weight. The process of application consists in applying this deactivating composition in proportions of the order of 0.25+0.05 liter per square meter of the surface, then washing with water this surface after a predetermined period.

Abstract: A rapid setting cementitious composition useful for making cement boards employs an insoluble form of anhydrous calcium sulfate (anhydrite) to accelerate setting and to permit reducing the amount of high alumina cement usage.

Abstract: The invention relates to an additive made up of chemical substances, non toxic for the human being neither for the environment, that stabilizes the attle without necessity of cooking neither compression, applicable for constructions/buildings in general, and specially, for housings of social interest, to be resistant, economic, stable, acoustic, thermal, etc. The material for construction including this additive, as well as its preparation process are also disclosed.

Abstract: A synthetic aggregate having a multiplicity of uses such as for mixing with a cementing material to form concrete, mortar or plaster is disclosed. The aggregate includes crushed fragments of a size which are capable of passing through mesh screen having sieve openings ranging from between about 19 mm and 75 microns. The aggregate fragments are made by curing and then crushing a compressed product. The compressed product is made by compressing an aqueous cementitious mixture comprising cement and at least one member selected from the group consisting of bottom ash and non-cementitious fly ash. The compressed product is cured so that it has a compressive strength of at least 600 psi.

Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: A mechanically activated pozzolan prepared from granitic quarry fines. Quarry fines are milled by a high-energy milling process to convert the essentially inert raw granitic fines into a chemically reactive state. When added to a portland cement mortar mixture, mechanically activated fines combined with calcium hydroxide to improve the strength of the cured mortar compared to a similar mixture prepared with raw fines. Mortars prepared with mechanically activated granitic fines typically show strength values comparable to or exceeding similar mortars made using fly ash as a pozzolan. In some instances, the strength of a mortar prepared with mechanically activated granitic quarry fines exceeded a mortar prepared using 100% portland cement as the cementitious component.

Abstract: The invention relates to a cement slurry for cementing an oil well or the like, the slurry having a density lying in the range 0.9 g/cm3 to 1.3 g/cm3, and being constituted by a solid fraction and a liquid fraction, having porosity (volume ratio of liquid fraction over solid fraction) lying in the range 38% to 50%. The solid fraction is constitued by a mixture of lightweight particles, microcement and optionally portland cement and gypsum. Such cements have remarkable mechanical properties due to their very low porosity in spite of having very low density.

Abstract: The present invention concerns a cement slurry with high permeability and good compressive strength, comprising a solid fraction constituted by: 35% to 80% (by volume) of particles with a mean size in the range 100 microns (&mgr;) to 800 &mgr;; 0% to 15% (by volume) of particles with a mean particle diameter in the range 0.1 microns to 10 microns; and 10% to 40% (by volume) of particles with a mean particle diameter in the range 20 &mgr; to 50 &mgr;; a fraction of said-solid particles being constituted by a cement, and preferably a further fraction by self-destructive particles; a liquid fraction in a water/solid ratio in the range 38% to 50% by volume; and a percentage of cells, provided by a gas or a liquid which is not miscible with water, in the range 30% to 60% of the final volume of the slurry.

Abstract: Delayed thixotropic cement compositions and methods of cementing in subterranean zones penetrated by well bores are provided. The novel cement compositions are basically comprised of a hydraulic cement, sufficient water to form a slurry and a water soluble delayed thixotropy imparting additive selected from the group consisting of carbonic acid and alkali metal carbonates.

Abstract: A facility for improving the environmental atmosphere of an interior space, which includes a negative ion discharger; a plurality of electric poles connected to the output wires of the negative ion discharger. The aforementioned negative ion discharger is placed in a corner of the interior space, and the plurality of electric poles are situated in the upper part of the interior space. By means of an active carbon layer beneath the floor indoors, an invisible shelter will be formed by the negative ions released from the negative ion discharger. Accordingly, the ion energy will be effectively decreased, and the particle condition of the indoor space will be harmonized.

Abstract: The invention concerns a composition in dry state for mortar or concrete, comprising a cement and an antishrinkage agent. The invention is characterized in that the antishrinkage agent consist of a calcium sulphate, particularly an anhydrous calcium sulphate, associated with at least a glycol ether.

Abstract: A mechanically activated pozzolan prepared from granitic quarry fines. Quarry fines are milled by a high-energy milling process to convert the essentially inert raw granitic fines into a chemically reactive state. When added to a portland cement mortar mixture, mechanically activated fines combined with calcium hydroxide to improve the strength of the cured mortar compared to a similar mixture prepared with raw fines. Mortars prepared with mechanically activated granitic fines typically show strength values comparable to or exceeding similar mortars made using fly ash as a pozzolan. In some instances, the strength of a mortar prepared with mechanically activated granitic quarry fines exceeded a mortar prepared using 100% portland cement as the cementitious component.

Abstract: An improved non-dispersing set retarder additive for foamed cements, cement compositions containing the additive, and methods of cementing in a subterranean zone penetrated by a well bore are provided. The set retarder additive includes a blend of a sulfonated lignin, preferably a lignosulfonate, with an alkali lignin, preferably a kraft lignin, having an organic sulfur content of 0-3.5% by weight in a ratio of about 6:4 to 8:2. The methods are basically comprised of the steps of preparing a foamed cement composition comprised of hydraulic cement, a non-dispersing set retarder, sufficient water to form a slurry, sufficient gas to foam the slurry and a foaming and foam stabilizing surfactant present in an amount sufficient to facilitate the formation of the foam and stabilize the foamed cement composition.

Abstract: Encapsulated water soluble chemicals for use in controlled time release applications, methods of encapsulating the chemicals and methods of using the encapsulated chemicals are provided. The methods of encapsulating the chemicals are basically comprised of forming a first coating of a dry hydrophobic film forming material or a sparingly soluble material which provides a dry shield on the chemical and then forming a second coating of a porous cross-linked hydrophilic polymer on the first coating which prevents the substantial dissolution of the resulting encapsulated chemical for a selected period of time.

Abstract: A method of treating metal-contaminated spent foundry sand, or other industrial waste, by combining the sand with a sulfite to produce insoluble metal sulfur oxide complexes that do not leach from the sand. The treated waste may also be processed to reducing “clumping,” thereby rendering the treated waste appropriate for use in another industrial process.