FIELD: well maintenance techniques. SUBSTANCE: method consists in separate supply of fuel and oxidizer to combustion chamber, their combustion, acceleration of gas mixture and direction to destroyed metal. Fuel and oxidizer are burnt at pressure exceeding well hydrostatic pressure at the lever of destroyed metal by 1.2-3.0 times. Before burning of metal, volumetric ratio of oxidizer and fuel is maintained equal to 1.2-3.0 and after burning of metal, the flow rate of oxidizer is increased by 2-10 times. Formed high-temperature mixture is accelerated up to transonic speed. Fuel and oxidizer before burning in combustion chamber are swirled in gas medium into coaxial whirl with peripheral velocity of 20-30 m/s and before acceleration the high-temperature mixture is expanded in radial direction by 1.2-5 times. After starting of metal burning, a part of total flow of oxidizer is supplied directly to zone of metal burning. EFFECT: higher efficiency in destroying metal in deep wells. 3 cl, 1 dwg
