Seismoelectric And Seismomagnetic Measurements In Fractured Borehole Models
Author(s)
Zhu, Zhenya; Toksoz, M. Nafi
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Other Contributors
Massachusetts Institute of Technology. Earth Resources Laboratory
Metadata
Show full item recordAbstract
Seismoelectric and seismomagnetic fields generated by acoustic waves in fluid-saturated
fractured borehole models are experimentally investigated with an electrode and a Halleffect sensor. In a borehole with a horizontal fracture, the Stoneley and flexural waves induce seismoelectric and seismomagnetic fields on the borehole wall and an electromagnetic wave propagating with light speed at the horizontal fracture. In a borehole with a vertical fracture, the acoustic field generated by a monopole or dipole source is similar to that in a borehole without a vertical fracture. However, the acoustic wave propagating along the vertical fracture induces seismoelectric and seismomagnetic fields, whose apparent velocities are equal to that. of a Stoneley wave. Experimental results show that two different kinds of electric and magnetic fields are generated by acoustic waves in borehole models with horizontal and/or vertical fractures. One is an electromagnetic wave propagating with light speed. The second is a stationary or localized seismoelectric and seismomagnetic field. Seismoelectric and seismomagnetic measurements might be a new logging technique for exploring fractures in a borehole.
Date issued
1999Publisher
Massachusetts Institute of Technology. Earth Resources Laboratory
Series/Report no.
Earth Resources Laboratory Industry Consortia Annual Report;1999-09