Simulation of SH‐TE seismoelectric logging

Abstract

The seismoelectric field excited by purely torsional loading applied directly to the borehole wall is considered. A brief formulation and some computed waveforms show the advantage of using SH-TE seismoelectric waves logging to measure shear velocity in a fluid-saturated porous formation. These waves are free of the borehole mode excitations that complicate other forms of acousto-electric well logging. Regardless of “electro-osmosis” effect in simulating, i.e., by supposing the acoustic field is not influenced by its induced electromagnetic field, the coupling governing equations for electromagnetic field are reduced to Maxwell equations with a propagation current source. It shows this simple algorithm is effective and the borehole seismoelectric conversion efficient is dependent on the electrokinetic coupling coefficient. For SH-TE seismoelectric waves logging, the receivers can be set in the borehole fluid.