Automatic Drift Time Estimation

The drift time is the difference in traveltime at the seismic frequency and the sonic logging frequency in anelastic media. The stationary synthetic seismogram needs drift time correction to tie the nonstationary seismic trace. Without knowledge of Q or a check-shot survey, dynamic time warping can estimate the drift time associated with apparent Q automatically by matching the stationary and nonstationary seismograms. After applying drift time correction to the stationary seismogram, the residual constant-phase between it and the nonstationary seismogram is small and almost constant with traveltime. The final crosscorrelation coefficient of stationary and nonstationary seismograms can be as high as 0.95.