METHOD OF PUMPING HYDROCHLORIC ACID INTO WATERED OIL FORMATION Russian patent published in 2024 - IPC E21B43/25 E21B37/06 E21B43/16 

FIELD: oil, gas and coke-chemical industry.

SUBSTANCE: invention relates to methods of oil production intensification from carbonate reservoirs by treatment of bottomhole formation zone with acid compositions and can be used to increase inflow of formation oil into wells, with use of which oil-saturated carbonate formations are developed. Method of pumping hydrochloric acid into a watered oil formation involves delivery of a concentrated acid to the formation interval inside a container in an anticorrosion design with upper and lower check valves. Hydrochloric acid with concentration of 46–99 % is pumped into a container under excess pressure at the wellhead from a vessel filled with acid solution under factory conditions. Hydrochloric acid solution is displaced from the container into the formation with a liquid inert to hydrochloric acid, which is pumped under pressure into the tubing string. Upper valve opens when pressure is created equal to the initial pressure in the vessel with acid. Lower valve opens when pressure is created equal to the sum of opening pressures of the upper valve and hydrostatic pressure created by a column of hydrochloric acid in the container.

EFFECT: providing highly concentrated hydrochloric acid to the surface of carbonate rocks, from the surface of which asphalt-resin-paraffin substances have been removed.

1 cl, 2 dwg