ACID TREATMENT METHOD OF PRODUCTIVE FORMATION Russian patent published in 2020 - IPC E21B43/27 E21B49/00 

FIELD: oil industry.

SUBSTANCE: invention relates to oil industry and can be used in development of oil deposit with low-permeability header. In the method of acid treatment of a productive formation, involving successive pumping into the formation of an alkaline composition and acid composition in combination with process exposures, as well as selling reaction products to the formation, before injecting the compositions, studies are carried out to determine the allowable injection pressure, acid composition, which increases permeability of the formation by at least 10 %, and chemical composition of reaction products with rock, calculating required volume of pumping per unit thickness of exposed productive formation and performing analysis to determine alkaline composition, most effectively neutralizing acid composition to pH, permissible for given well, and its volume per unit thickness of the exposed payout bed for dissolving the reaction products to a value sufficient for further vortexing into the formation. First, the selected acid composition is pumped into the formation in the required volume, calculated based on the length of the exposed productive formation, and with pressure not exceeding 80 % of the allowable value. After process holding sufficient for reaction with bed rock, selected alkaline composition of required volume is pumped with pressure not higher than 80 % of allowable. Reaction products are further supplied to the formation into remote zones not involved in development at this stage, after process conditioning sufficient for neutralization of acid composition.

EFFECT: technical result is higher efficiency of acid treatment of productive formation, possibility of operation with different in composition collectors.

1 cl, 1 ex