Abstract: A method for the preparation of a scale inhibitor and a method of inhibiting the formation of scale uses a water soluble polymeric gelling agent, in particular synthetic polymer, which has been degraded and reduced in its molecular weight.

Abstract: A method to reduce the viscosity of viscosified treatment fluids is disclosed herein. The method includes a water soluble polymer as viscosifying agent, preferably a synthetic water soluble polymer, optionally a crosslinker for the water soluble polymer, a breaker system containing an organic peroxide, mixing the viscosified treatment fluid and the breaker composition and allowing the viscosified treatment fluid and the breaker composition to interact whereby the viscosity of the viscosified treatment is reduced. The application of the process in the production of oil and gas is also discussed.

Abstract: A method to reduce the viscosity of viscosified treatment fluids is disclosed herein. The method includes a water soluble polymer, a breaker system containing at least one aliphatic azo-compound, mixing the viscosified treatment fluid and the breaker composition and allowing the viscosified treatment fluid and the breaker composition to interact whereby the viscosity of the viscosified treatment is reduced. The application of the process in the production of oil and gas and to the treatment fluids is also discussed.

Abstract: The present invention relates to a method to reduce the water loss in slurries and solutions used in oil field or gas field operations, for example for drilling, cementing and completion operations by adding a copolymer having a high molecular weight characterized by a K value of at least 300, said copolymer comprising structural units derived from monomers having sulfonic acid or derivative thereof, phosphonic acid or derivative thereof and acrylamide functionality.

Abstract: The invention relates to a temperature-stable hydrogel comprising electrolytic water and a copolymer cross-linked to multivalent metal ions. The invention is characterized in that the copolymer contains at least structural units which are derived at up to 0.005-20% by weight from an ethylenically unsaturated phosphonic acid and alkali metal salts thereof and/or ammonia salts, up to 5-40% by weight from an ethylenically unsaturated sulfuric acid and alkali metal salts thereof and/or ammonia salts and up to 5-94.995% by weight from an amide of an ethylenically unsaturated carboxylic acid selected from the group of acrylamide, methacrylamide and/or C1-C4 alkyl derivatives, wherein the percentages are based on the total mass of the monomers used during copolymerization, and that the multivalent metal ions for cross-linking of the copolymers belong to the groups IIIA, IVB, VB, VIIIB and/or VIIIB of the periodic system of elements.

Abstract: A method for synthesize hydrogels, that may be used in fracturing operations, with increased viscosity from a solution containing water, a copolymer and a dissolved salt of an alkaline metal, an earth alkaline metal and/or an organic amine by addition of a zirconium compound as a crosslinker which comprises: i) providing a copolymer containing structural units of formula I, structural units of formula II, and structural units of formula Ill ii) preparing an aqueous solution by adding the copolymer prepared in step i) to a solution comprising water and the dissolved salt, iii) forming a network of a hydrogel by addition of at least one zirconium-compound to the aqueous solution prepared in step ii), and iv) selecting the amount of the dissolved salt in the hydrogel to range from 0.15 and 10 weight %.

Abstract: The invention relates to a temperature-stable hydrogel comprising electrolytic water and a copolymer cross-linked to multivalent metal ions. The invention is characterized in that the copolymer contains at least structural units which are derived at up to 0.005-20% by weight from an ethylenically unsaturated phosphonic acid and alkali metal salts thereof and/or ammonia salts, up to 5-40% by weight from an ethylenically unsaturated sulfuric acid and alkali metal salts thereof and/or ammonia salts and up to 5-94.995% by weight from an amide of an ethylenically unsaturated carboxylic acid selected from the group of acrylamide, methacrylamide and/or C1-C4 alkyl derivatives, wherein the percentages are based on the total mass of the monomers used during copolymerization, and that the multivalent metal ions for cross-linking of the copolymers belong to the groups IIIA, IVB, VB, VIIIB and/or VIIIB of the periodic system of elements.

Abstract: An electrolyte-containing aqueous polymer solution is described with a salt content of 5% to 35% by weight with respect to the total weight of the polymer solution, containing at least one dissolved synthetic copolymer which contains structural units which are derived from (i) at least one amide of an ethylenically unsaturated carbonic acid and from (ii) at least one ethylenically unsaturated sulphonic acid or their alkali metal salts and/or ammonium salts, and containing at least one non-ionic surfactant selected from the group formed by alkoxylated fatty alcohols, alkoxylated alkylphenols and/or alkoxylated fatty acids, with the proviso that the mean degree of alkoxylation of said surfactants is 8-10. The aqueous polymer solution is used for the tertiary recovery of crude petroleum and is characterized by very good filtration behaviour, in particular in the presence of saline water.

Abstract: Disclosed are stabilized aqueous polymer compositions containing A) a stabilizing amount of a least a sulfur dye or containing a stabilizing amount of a sulfur dye with a compound comprising a heterocyclic system containing nitrogen and sulphur as ring heteroatoms and B) at least one polymer comprising groups which are capable of complex formation with ions. The aqueous polymer compositions are stabilized against thermal or other degradation processes of the polymer by addition of component A) to allow their use even under harsh conditions.