METHOD OF TREATMENT OF BOTTOM-HOLE FORMATION ZONE Russian patent published in 2003 - IPC

FIELD: production of liquid flowing and gaseous media from drilled wells, particularly, intensification of oil and gas producing wells with use of corrosives; applicable in oil and gas producing industry, in treatment of bottom-hole formation zones. SUBSTANCE: method includes successive injection into formation of solution containing alkali in the form of alkali metal hydroxide, displacement fluid and two acid solutions in two stages. First, solution containing hydrochloric acid and then solution of hydrofluoric acid are injected. Well completion is carried out without holding solutions for reaction in formation. Acid solutions are separated by displacement fluid in the form of gas. Concentration of solutions shall provide for minimal viscosities of products with preservation of acids reactivity. Concentration of hydrochloric acid is taken equal to 8-0 mas.%, and hydrofluoric acid, to 6-8 mas. %. Special tubing is used for removal of reaction products, delivery of reagents to bottom-hole zone and control in the course of injection. EFFECT: higher efficiency of treatment due to increased mobility of reaction products owing to reduction of their viscosity and temporary increase of energetics of bottom-hole formation zone. 3 cl, 1 tbl