ACID COMPOSITION FOR PROCESSING THE SURFACE ZONE OF CARBONATE FORMATION Russian patent published in 2018 - IPC C09K8/74 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil industry and can be used in acidizing the bottomhole zone of a carbonate formation. Acid composition for treatment of the bottomhole formation zone contains, mass%: sulfamic acid 5.0–15.0; surfactant – 0.05–1.5; ammonium acetate 0–6.0; acetic acid 1.0–10.0; a corrosion inhibitor and water, characterized in that said composition further comprises acetic acid 0.1–1.5; water with mineralization not more than 1 g/dm³ – the rest. As the SAS, oxyethylated alkylphenol or a hydroalcoholic solution of non-ionic surfactants (polyethylene glycol monoalkylphenyl ether 90 % by weight and alkyl dimethylbenzylammonium chloride 10 % by weight) is used, as a corrosion inhibitor, urea, or thiourea, or a mixture of carbamide and thiourea in a weight ratio of 1:1, or neating.

EFFECT: increasing the efficiency of conducting acid treatment of the carbonate formation by reducing the corrosiveness with respect to the field equipment made of steel, and an increase in the dissolving power of the acid composition with respect to the carbonate formation.

1 cl, 1 dwg, 1 tbl