ИСТИНА

Electromagnetic field excites acoustic field in a porous elastic medium saturated with fluid electrolyte due to electrokinetic conversion effect. Our solution of finite-difference equations, obtained from Pride’s equations describing this process, showed that acoustic field consists of the same types of waves as in the process of traditional acoustic logging plus fast wave, which propagates almost instantly. Amplitude of this wave is sensitive to the formation permeability and can be registered, if proper electric emitter is used. Modified Pride’s equations, which take into account the effect of Joule heating on the propagation of acoustic waves, are used in this work. It follows from numerical results that Joule heating can make significant contribution to the acoustic field.