the medium leads to the appearance of shear vibrations in the well bore region whose vector of oscillating velocity v r is 53 is directed along the radiator axis diagram 54 shows the characteristic distribution of displacement amplitudes of shear vibrations u03be z mz as a result an acoustic flow 55 is produced in the well bore region 50 due to the superposition of longitudinal and shears waves with speed u f and characteristic wavelength u03bb 4 the method described in the preceding paragraphs is implemented in particular in the device shown in fig3 where said device is situated within the well therefore present invention also considers an electro acoustic device 20 which comprises a closed case 200 preferably of cylindrical shape and known as a sonde which is lowered into the well by an armoured cable 22 comprised preferably by wires and in which one or more electrical conductors 21 are provided with said armoured cable 22 the closed case 200 is constructed with a material that transmits the vibrations the casing 200 has two sections an upper case 23 and a lower case 201 the lower case 201 at its furthest end has two internal cavities 25 and 302 cavity 25 communicates with the exterior by means of small holes 26 the fluid 18 to be recovered from the well bore region may flow through these small holes 26 into the cavity 25 this fluid once it has filled the internal cavity 25 allows to compensate the pressure in the well bore region with that of the device 29 the internal cavity 302 is flooded with a cooling liquid 29 which acts on.