METHOD AND DEVICE FOR TWO-CHAMBER HELMHOLZ SPRAY OSCILLATOR FOR GENERATING PRESSURE WAVES AT THE BOTTOM HOLE Russian patent published in 2017 - IPC E21B43/25 E21B28/00 E21B43/16 F15B21/12 

FIELD: oil industry.

SUBSTANCE: group of inventions refers to oil industry and is intended for removing solid deposits from walls of casing pipes and perforation apertures, decolmatation of the formation bottomhole zone and increasing mobility of the formation fluids. In the method of pressure waves generation at the bottom of the well a Helmholz spray oscillator (HSO) is installed on the lower end of a tubing string (TS), representing an oscillating system excited with a spray of fluid flowing through it and consisting of a spray generator positioned inside the chamber of the volume resonator. Herewith primary pressure oscillations of certain frequency in a spray of liquid are generated with the spray generator and the oscillating system is excited with them. Primary pressure oscillations are amplified in the chamber of the volume resonator, natural frequency of which is tuned with resonance to generation frequency of primary pressure oscillations. Pressure waves at the bottom hole are created. Herewith another chamber with an opening is installed behind the chamber of the volume resonator, thus forming the oscillating system having three natural frequencies not corresponding to natural frequencies of its separate elements. Primary pressure oscillations generation frequency is adjusted at the highest natural frequency of the oscillation system. Herewith the oscillating system on all the other natural frequencies is excited and pressure oscillations are generated on the lowest natural frequency.

EFFECT: technical result is higher efficiency of generation of low-frequency oscillations at the bottom hole with a high-speed spray.

2 cl, 2 dwg