COMPOSITION FOR ACID TREATMENT OF NEAR-WELLBORE ZONE OF RESERVOIR (OPTIONS) Russian patent published in 2019 - IPC C09K8/74 

FIELD: oil industry.

SUBSTANCE: composition for the acid treatment of the near-wellbore zone of the reservoir in the first embodiment contains, vol.%: Intens-1 iron converter or TN-SZhKS 0.5–1.0; water-soluble demulsifier TN-DEKS 1–3; surfactant SAS Surfasol or TN-MS-2 0.2–0.3; acid corrosion inhibitor TN-IKKS 0.5–1; isopropyl alcohol 1–2; an aqueous solution of synthetic hydrochloric acid 30–36 % concentration the rest. Composition according to the second variant contains, vol.%: iron Intens-1 or TN-SZhKS neutralizer 0.5–1.0; water-soluble demulsifier TN-DEKS 1–3; SAS Surfasol or TN-MS-2 0.2–0.3; acid corrosion inhibitor TN-IKKS 0.5–1; isopropyl alcohol 1–2; technical liquid lignosulfonates 18–28; an aqueous solution of synthetic hydrochloric acid 30–36 % concentration the rest. Composition according to the third variant contains, vol.%: iron Intens-1 or TN-SZhKS neutralizer 0.5–1.0; water-soluble demulsifier TN-DEKS 1–3; surfactant SAS Surfasol or TN-MS-2 0.2–0.3; acid corrosion inhibitor TN-IKKS 0.5–1; isopropyl alcohol 1–2; aqueous solution of hydrofluoric acid 40–70 % concentration of 3–5; an aqueous solution of synthetic hydrochloric acid 30–36 % concentration the rest. Composition according to the fourth variant contains, vol.%: iron Intens-1 or TN-SZhKS neutralizer 0.5–1.0; water-soluble demulsifier TN-DEKS 1–3; surfactant SAS Surfasol or TN-MS-2 0.2–0.3; acid corrosion inhibitor TN-IKKS 0.5–1; isopropyl alcohol 1–2; polyacrylamide aqueous solution of 3–5 % concentration or modified starch aqueous solution of 3–5 % concentration 3–8; an aqueous solution of synthetic hydrochloric acid 30–36 % concentration the rest.

EFFECT: improved physicochemical and technological properties of the composition, complete prevention of precipitation of clogging gel-like iron-containing sediments during the treatment with the composition, inhibition of the formation of emulsions, full removal of reaction products from the reservoir in the process of development with simultaneous reduction of economic costs.

4 cl, 2 tbl, 4 ex