Patent EA-001510-B1 (EA)
Title: Method for applying an acoustic resonance action on gas- and oil- bearing beds and device for realising the same
IPC: E21B28/00
Filed: 1999-02-09
Abstract: 1. A method for applying an acoustic resonance action on gas - and oil - bearing bed comprising diagnosing the area that is close to the bottom of a well, wherein said method comprises generating an acoustic field and correcting the emission mode parameters according to the results provided by a feedback link, characterized in that the acoustic action is applied step by step using a vertical acoustic field as well as a horizontal and circular acoustic field simultaneously, wherein the first step comprises generating a standing wave in the space closed by a tube, while the second step comprises generating a travelling wave having a frequency which is close to the resonance frequency of the structure of the fluid-bearing bed, said feedback link consists in the frequency-dependence of the amplitude of the acoustic signal which is dispersed in the return direction. 2. The method according to claim 1, characterized in that the intensity of the acoustic emission in the perforation zone is set to be at least 10 W/cm<2>. 3. A device for applying an acoustic resonance action on gas - and oil - bearing bed comprising a  ground control unit, cable-connected to a well instrument, said well instrument comprises a generator, an acoustic emitter and a sensor, characterized in that said well instrument is designed in the shape of two sections connected by a cable, the upper section includes a generator, while the lower section communicates with the surrounding medium and contains a feedback link sensor and at least one acoustic emitter, said the acoustic emitter comprises at least one acoustic wave reflector arranged coaxially with said emitter, said reflector has a conical surface whose summit is directed towards the emitter at a fixed distance A from the end thereof. 4. The device according to claim 3, characterized in that the distance A between the end surface of the acoustic emitter and the summit of the conical surface of the acoustic wave reflector is determined based on a condition of forming a standing wave by the formula: A = nλ/2 - b, where: n = 1,2,3... λ = the length of a travelling wave b = radius of the tube inner wall 5. The device according to claim 3, characterized in that the reflector has a conical surface whose summit is directed towards the emitter at an angle of 90 degree C at said summit. 6. The device according to claim 3, characterized in that the lower section of the well instrument communicates with the surrounding medium through rectangular windows made in casing wall in the zones of location of the acoustic wave reflectors. 7. The device according to claim 3, characterized in that the lower portion of the well instrument ends up in an acoustic concentrator. 8. The device according to claim 6, characterized in that the end of said acoustic concentrator is provided with a disk-shaped belt for mechanical clearing of deposits from the tube walls. 9. The device according to claim 3, characterized in that the lower portion of the well instrument ends up in an echometer.