SPWLA Twenty-Second Annual Logging Symposium, JUNE 23-26, 1981        PAPER O

PAPER O

 

 VELOCITY AND ATTENUATION FROM FULL WAVEFORM ACOUSTIC LOGS

 

Chuen H. Cheng, M. Nafi Toksoz and Mark E. Willis

Massachusetts Institute of Technology

Cambridge, MA

ABSTRACT

 

Methods for the determination of P and S wave velocity and attenuation from full waveform acoustic logs are presented in this paper. For P wave velocities, the best method is based on event detection and fine adjustments by correlation and interpolation. For S wave velocities, the P

wave pulse is correlated with the rest of the record to find the S wave arrival, which is then correlated with the next record to obtain the move-out. For P wave attenuation, a direct comparison of the peak amplitudes of two records with different source-receiver separations is used with geometrical spreading taken into account. For S wave attenuation the best method seems to be the analysis of the guided waves spectral amplitudes at two or more frequencies and then solve for the S wave attenuation using the partition coefficients.