ACID COMPOSITION FOR TREATMENT OF LOW-PERMEABLE TERRIGENOUS HEADERS WITH HIGH CARBONATE CONTENT AND METHOD OF ACID TREATMENT OF BOTTOM-HOLE FORMATION ZONE WITH BY USING IT Russian patent published in 2010 - IPC C09K8/74 E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: acid composition for treatment of low-permeable terrigenous headers with high carbonate content includes the following, wt %: alkylbenzenesulfoacid containing 12-14 atoms of carbon in alkyl residue, 3.5-5.5, preparation OC-20 2.5-5.5, ammonium chloride 3.5-6.5, 24% solution of inhibited chlorhydric acid 14.0-18.0, methanol 12.0-16.0, grain oil 4.0-8.0, acetic acid 6.0-12.0, citric acid 2.5-4.5, "IKU-118" rust inhibitor 0.1-0.5, and fresh water is the rest. Acid treatment method of bottom-hole zone of terrigenous headers with high carbonate content involves subsequent pumping to the well of flush fluid and 1.5-3.0% solution of ammonium chloride is used as flush fluid in quantity of 0.5-1.0 m³ per 1 m of perforated thickness of the bed, and acid composition in quantity of 0.5-2.0 m³ per 1 m of perforated thickness of the bed, its pushing to the bed by using the above flush fluid in quantity of 1.0-3.0 m³ and liquid for pushing and as the latter there used is fresh or mineralised water or water-oil emulsion, or oil, exposure for reaction during not more than 8 hours and further removal of reaction products; as acid composition there used is the above acid composition or its solution obtained at dilution of the above acid composition with fresh water or with 3-24% solution of inhibited chlorhydric acid in ratio of the above acid composition: fresh water or 3-24% solution of inhibited chlorhydric acid 1:1-1:9 respectively.

EFFECT: increasing acid treatment efficiency.

2 cl, 3 tbl, 2 ex