METHOD OF GAS-ACIDIC OIL INFLOW STIMULATION IN OIL EXTRACTION AND INJECTION WELL BED Russian patent published in 2010 - IPC E21B43/27 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed method comprises injecting acidic foam forming compound through well into pay in circulation conditions at the rate of 0.3 to 2.5 m³ per metre of the bed perforated thickness and with open external casing gate into oil well tubing (OWT) volume, injecting, in some 20 to 60 seconds, neutral gas at 10 to 65 MPa at the rate of 100 to 1200 m³/h. Note that neutral gas starting pressure is preliminary defined from the formula enclosed herewith. In case maximum tolerable pressure in neutral gas feed unit is reached or maximum tolerable operating pressure of operated string is reached, injection of neutral gas is stopped to go on injecting acidic foam forming compound. After injecting acidic foam forming compound, gate is shut off or parker is seated. Remaining volume of acidic foam forming compound is injected. Formed foam acid is injected into bed by service water or oil in amount of the sum of well OWT internal volume and production string volume from well OWT well shoe to lower perforation holes. Service curing is effected and waste acidic foam forming compound is removed. Bed is drained, well is developed through hole clearance by injecting oil or service water with surfactant through gas bank in amount equal to well hole clearance.

EFFECT: increased bed permeability.

5 cl, 4 ex