FIELD: chemistry.
SUBSTANCE: invention relates to compositions and fluids used in the treatment of wells by hydraulic fracturing. Gel composition comprising an acrylamide polymer or a copolymer crosslinked with a dialdehyde obtained by mixing an acrylamide polymer or a copolymer with a dialdehyde in an aqueous solution at a pH in the range of about 9.0 to about 11, wherein the acrylamide polymer or copolymer has a charge in the range of about 15 to about 35 mol%, and the molar ratio of the dialdehyde to the monomers of the acrylamide polymer or copolymer is in the range approximately greater than about 1.1 to about 2.0. Well treatment fluid containing said gel composition. Process for preparing a gel composition, comprising mixing or reacting an acrylamide polymer or copolymer with a dialdehyde component in an aqueous medium with a pH in the range of about 9.0 to about 11, wherein the molar ratio of the dialdehyde to the monomers of the acrylamide polymer or copolymer is in the range approximately greater than about 1.1 to about 2.0, at a temperature and for a period of time, sufficient to produce a gel composition; wherein the acrylamide polymer or copolymer has a charge in the range from about 15 to about 35 mol%. Method of treating a well where said gel composition is injected into the wellbore. Method of treating a well, comprising introducing into the wellbore a composition comprising an acrylamide polymer or copolymer; introducing into the wellbore a composition containing a dialdehyde, and introducing a pH modifying agent into the wellbore in an amount sufficient to form a solution in the borehole with a pH in the range of about 9.0 to about 11, to obtain said gel composition in situ. Invention is developed in dependent items of the formula.
EFFECT: technical result is the increase in processing efficiency.
21 cl, 3 ex, 3 tbl, 2 dwg
