FIELD: oil and gas industry.
SUBSTANCE: method of multi-stage treatment of injection well bottomhole zone in terrigenous and carbonate formations includes hydrochloric acid treatment with acid composition of 0.5-1m3/m volume followed by pressing with aqueous solution of colloidal silicon dioxide nanoparticles or aqueous solution of surface-active substance of 2-3 m3/m volume; clay-acid treatment with clay-acid composition based on hydrochloric and hydrofluoric acids with 0.8 0.5 m3/m volume followed by pressing with aqueous solution of colloidal silicon dioxide nanoparticles or an aqueous solution of surface-active substance of 2-3 m3/m volume, treatment with hydrocarbon solvent of 0.5 m3/m volume and with clay-acid composition based on hydrochloric and hydrofluoric acids with 0.5 m3/m volume then by spraying aqueous solution of colloidal silicon dioxide nanoparticles or aqueous solution of surface-active substance of 2-3 m3/m volume. The following composition is used as acid composition, vol %: 30% hydrochloric acid 50-63; diethylene glycol 6-16; acetic acid 1-3; water-repellent agent based on amides, 1-3; corrosion inhibitor, 1.5-2; the rest is process water. The following composition is used as the clay-acid composition, vol %: 30% hydrochloric acid 48-60; hydrofluoric acid 1-4; diethylene glycol 6-16; acetic acid 1-3; water-repellent agent based on amides, 1-3; corrosion inhibitor, 1.5-2; the rest is process water. As aqueous solution of colloidal silicon dioxide nanoparticles, 1-2%- aqueous solution of colloidal silicon dioxide nanoparticles is used, containing wt %: colloidal silicon dioxide in acrylic acid, 32-40; propylene glycol monomethyl ether, 59.5-67.5; the rest is water. Aqueous solution of surface-active substance is 2-4% aqueous solution of surface-active substance containing, wt %: diethylene glycol, 1-3; hydrophobic agent based on amides, 0.5-2; the rest is process water. Solvent based on toluene fraction of straight-run gasoline or based on an aromatic hydrocarbon concentrateC10 is used a hydrocarbon solvent.
EFFECT: increased efficiency injection wells, reduced time for implementation of the method, its simplification and reduced cost.
2 cl, 7 dwg
