4.5.16.3 Statistical Wavelet Extraction

Statistical wavelets can be extracted from the seismic data.

The User first needs to choose the input seismic, i.e 3D volume or 2D line.

If 3D seismic is selected, the following window pops up:

It is recommended to use a sub-selection of the seismic data, e.g. every 10th inline/crossline, and to use horizons to guide the extraction. The extract length of the seismic data should be at least 1 second TWT.

The wavelet length should never be too small (min 50ms), or too large (200ms max). A rule of thumb is that the first side lobe should be fully contained in the wavelet.

The extraction is performed using the following workflow:

1. Seismic traces are extracted and tapered
2. The auto-correlation of the seismic traces is computed, using the length of the desired wavelet
3. The frequency spectrum of the auto-correlation is computed.
4. The square root of the modulus of the frequency spectrum is taken, the zero Hertz component is muted to zero.
5. The inverse FFT is computed.
6. The zero phase wavelet is the real part of the inverse FFT output

The output phase rotation cannot be set in the current version. It is being implemented.

The Wavelet extraction in 2D line is shown below: