ACID COMPOSITION FOR TREATMENT OF TERRIGENOUS RESERVOIRS (VERSIONS) Russian patent published in 2021 - IPC C09K8/54 C09K8/74 C09K8/78 E21B43/27 

FIELD: oil industry.

SUBSTANCE: group of inventions relates to the oil-producing industry and, in particular, to compositions for bottomhole acidizing of wells. Acidic composition includes the following elements: inhibited hydrochloric acid, ammonium bifluoride or ammonium fluoride, auxiliary acid, isopropyl alcohol, surface-active agent (SAA), and water. In this case, the composition additionally contains an organic solvent - butyl cellosolve. As an auxiliary acid, the composition comprises acetic acid, and as SAA - neonol AF_9-12 or sulfanol, or an auxiliary substance OP-10 with the following ratio of components, weight (wt)%: inhibited hydrochloric acid - 10-15; ammonium bifluoride or ammonium fluoride - 7-14; acetic acid - 3-5; isopropyl alcohol - 5-10; SAA - 0.1-0.3; butyl cellosolve - 7-12; and water is the remaining part.

EFFECT: increased efficiency of acid treatment of a terrigenous reservoir due to a slowdown in the rate of reaction with the rock under conditions of the reservoir temperature, low values of the surface tension at the boundary with reservoir hydrocarbons, low corrosion rate, and prevention of the stable non-acid emulsions formation.

3 cl, 3 ex, 2 tbl