Patent ID: 6205087
Filing Date: 2001-03-20
Classification: G01V

Abstract:
A sonic logging method for determining characteristics of a formation through which a borehole passes using a downhole tool which is located in the borehole so as to be moveable up and down and coupled to ground surface processing apparatus by means of a logging cable, the downhole tool including: (i) at least one sonic wave generator and at least once receiver spaced apart from each other; and (ii) a downhole processing device operatively coupled to the generator and receiver and also to the ground surface processing apparatus through the logging cable, the method comprising:(a) locating the downhole tool in the borehole;(b) generating a sonic wave signal with the at least one generator;(c) receiving the sonic wave signal with the at least one generator;(d) processing a received signal using the downhole processing device and determining an arrival time for the sonic wave signal at the receiver; and(e) transmitting the determined arrival time to the ground surface processing equipment through the logging cable.