Abstract: A polymer composition may include one or more monomeric units, with an internal crosslinker, internal breaker, scale control additive or a combination thereof.

Abstract: A polymer composition may include one or more monomeric units, with an internal crosslinker, internal breaker, scale control additive or a combination thereof.

Abstract: An environmentally acceptable water-in-oil microemulsion composition includes at least one emulsifying surfactant, at least one biodegradable hydrocarbon solvent, at least one co-solvent, at least one hydrocarbon co-surfactant, and water. The microemulsion composition may be used in a method for rendering fluids from oil external to water external. The microemulsion composition may be combined with water or a water based fluid to produce a spacer fluid utilized in removing oil and oil-residues from a surface, particularly that of wellbores in the drilling of oil and gas wells.

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: A plugging fluid for plugging a subterranean formation zone surrounding a drill hole comprises an emulsion comprising a dispersed aqueous phase containing an aqueous base and a continuous hydrophobic phase containing a polymer consisting of a grafted cellulose ether derivative, a surfactant and a crosslinking activator of the polymer. The polymer is preferably 2-hydroxyethyl cellulose grafted with vinyl phosphonic acid. Upon shearing, preferably through the drilling bit, the emulsion inverts so that the rupture of the emulsion droplets releases the crosslinking activator into the water phase thus forming a gel structure.

Abstract: A plugging fluid for plugging a subterranean formation zone surrounding a drill hole comprises an emulsion comprising a dispersed aqueous phase containing an aqueous base and a continuous hydrophobic phase containing a polymer consisting of a grafted cellulose ether derivative, a surfactant and a crosslinking activator of the polymer. The polymer is preferably 2-hydroxyethyl cellulose grafted with vinyl phosphonic acid. Upon shearing, preferably through the drilling bit, the emulsion inverts so that the rupture of the emulsion droplets releases the crosslinking activator into the water phase thus forming a gel structure.

Abstract: The present invention provides improved well cementing compositions 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 compositions 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: A cementing composition comprising a hydraulic cement powder dispersed in a solvent that is miscible both with water and hydrocarbons to make a slurry. The cement powder can be made up simply of hydraulic cement materials or can be a mixture of such materials with particles that are inert or reactive with cement. The composition can also include surfactants or retarders. The composition is used to plug water production in a well while leaving hydrocarbon production unaffected.

Abstract: A plugging fluid for plugging a subterranean formation zone surrounding a drill hole comprises an emulsion comprising a dispersed aqueous phase containing an aqueous base and a continuous hydrophobic phase containing a polymer consisting of a grafted cellulose ether derivative, a surfactant and a crosslinking activator of the polymer. The polymer is preferably 2-hydroxyethyl cellulose grafted with vinyl phosphonic acid. Upon shearing, preferably through the drilling bit, the emulsion inverts so that the rupture of the emulsion droplets releases the crosslinking activator into the water phase thus forming a gel structure.

Abstract: A plugging fluid for plugging a subterranean formation zone surrounding a drill hole comprises an emulsion comprising a dispersed aqueous phase containing an aqueous base and a continuous hydrophobic phase containing a polymer consisting of a grafted cellulose ether derivative, a surfactant and a crosslinking activator of the polymer. The polymer is preferably 2-hydroxyethyl cellulose grafted with vinyl phosphonic acid. Upon shearing, preferably through the drilling bit, the emulsion inverts so that the rupture of the emulsion droplets releases the crosslinking activator into the water phase thus forming a gel structure.

Abstract: A method is provided for controlling the delay time of aqueous borate-crosslinked polysaccharide-based fluids for hydraulic fracturing and related applications which allows on-the-fly control of the delay time without comprising overall fluid integrity. Without having to modify the total boron content nor pH of the fracturing fluid, the delay time is controlled by adding a polyol to the fracturing fluid at a first rate, determining the resulting delay time and then adjusting the rate of the polyol addition to the fracturing fluid until the desired delay time is achieved.