Method and device for transmission of radial elastic waves in a medium materials by induction increasing

摘要

- method and device of the transmission of elastic waves radial in a medium by electromagnetic induction, which can be used in particular for generating seismic waves in the wells tube-containing or not, or in a mass of radial eau.l' wave emission is obtained essentially by extending radially a metal tube (1) in contact with the medium under the effect of a magnetic pressure generated by electromagnetic induction, the elastic waves are created in the medium under the effect of this expansion. The pressure is obtained by connecting a coil (2) placed in the axis of the tube with a current generator (3): the generator of the shock generator at a variable frequency. The winding pitch of the coil (2) can be constant or variable. The tube (1) may be, for example, mounted in a well or hole or well be a tube portion of a cased well. It may also be the side wall of a sealed enclosure which are immersed in a mass of water in order to produce the acoustic waves or seismic. - applications to prospection or the seismic monitoring of the under - ground, for example.