ABSTRACT
A borehole televiewer uses ultrasonic waves and is a kind of reflection logging. The amplitude of reflected wave depends oc the medium density and seismic velocity. Therefore BHTV method can get an image log of a borehole wall when drilling in a muddy fluid, providing an excellent method for slip surface exploration.
Determining the slip surface from the data of BHTV, it must have the following conditions due to the characteristics of re-sliding type landslide.
The remarkable low amplitude zone (max, min).
Fragments filling the clay structure in the low amplitude zone.
Remarkable changes of amplitude at the top and bottom of the low amplitude zone.
Gently sloped structure in the low amplitude zone (the dip conforms to the geological condition of the parent rock).
