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

摘要

A method and device for emitting radial seismic waves in a material medium by electromagnetic induction, used notably for generating seismic waves in cased or uncased wells or in a water mass is disclosed. Emission of radial waves is essentially obtained by radially expanding a metal tube (1) under the effect of a magnetic pressure generated by electromagnetic induction with elastic waves being created in the medium under the effect of this expansion. The magnetic pressure is obtained by connecting a coil (2) in line with the tube to a current generator (3). The winding pitch of coil (2) can be constant or variable. Tube (1) can for example be added into a well or hole or it can be a tube portion of a cased well.