PROCEDURE FOR TREATMENT OF BOTTOMHOLE ZONE OF WELL Russian patent published in 2010 - IPC E21B43/27 

FIELD: gas-and-oil industry.

SUBSTANCE: procedure for treatment of bottomhole zone of well consists in lowering assembly into well; from bottom-up assembly is composed of plug, shank end, lifting pipe, filter, flow string, packer and flow string to well head; also filter is positioned opposite to perforation interval. The well is filled up with oil to the wellhead. At a rate of 0.4-0.6 m³ per each metre of interval of perforation there is prepared the first portion of mixture of acid and surface active substance ML-81B heated to 70-80°C. The first portion of the said mixture is supplied via the flow string to the bottomhole zone at an opened tube gate. By oil forcing-through it is placed in annular space till complete volume of the portion fills annular space from the shoe of the perforation interval upward. Further, the tube gate is shut, the first portion is forced through with oil into a reservoir via annular space under 3-5 MPa pressure at the wellhead. Annular space is straddled with the packer. During 2-3 hours there is performed process conditioning for reaction of acid with rock. Further, the well is swabbed to extraction of reaction products and reservoir fluid to 5-6 pH. Simultaneously there is prepared the second portion of heated to 70-80°C mixture of acid and surface-active substance ML-81B at 15-25% volume more, than the first portion. Immediately after swabbing and without stops it is pumped and forced through with oil at 3-5 MPa pressure at the wellhead, process conditioned for reaction of acid with rock during 2-3 hours and swabbed to extraction of reaction products and reservoir fluid till 5-6 pH.

EFFECT: raised efficiency of reservoir bottomhole hole zone treatment.

2 cl, 1 ex