OIL RECOVERY COMPOSITION, METHOD AND REAGENT Russian patent published in 2021 - IPC C09K8/88 E21B43/22 

FIELD: oil production.

SUBSTANCE: present invention can be used to increase oil production at late stages of development of productive formations with terrigenous and carbonate reservoirs. Oil production composition containing particles of disperse gels of hydrolysed polyacrylamide, associated with them trivalent metal ions and water, where each of particles contains 0.5–5 wt % polyacrylamide molecules with degree of hydrolysis of 5–30 %, structurally bonded within one particle by Cr⁺³ ions and molecules of formation or merchandise water in particles with volume of 1–1000 mm³, wherein the gel material has a modulus of elasticity within 2–80 kPa, and in the total volume of the composition, particles occupy 30–90 % of its volume. Method of oil production, including pumping into injection well of water from system of maintaining formation pressure and fringe of composition specified above, in which said composition is synthesized in process vessel directly at well in reaction between partially swollen polyacrylamide particles and Cr⁺³ ions—ionic modifier in suspended water at their total concentration of up to 2 % in water until stabilization of precipitate volume of disperse gels, but not less than 30 minutes. Reagent for producing said composition contains a powdery composition containing 2–6 % of basic chromium sulphate or chromic alum and polyacrylamide—the rest.

EFFECT: technical result is the oil production process simplification by excluding the stage of preliminary treatment of the polymer by ionizing radiation, expansion of application area on formations with temperature over 80 °C and higher efficiency of injectivity profile injection wells with inhomogeneous formations due to improved elastic properties of gels.

3 cl, 2 ex, 1 tbl, 11 dwg