Geophysical Insights hosting the 2018 Oil & Gas Machine Learning Symposium in Houston on September 27, 2018
Introduction to Machine Learning for Multi–Attribute Interpretation and AASPI attributes - A 1-day, DGS Continuing Education course in Denver, CO on September 18th
Dr. Tom Smith presenting on Machine Learning at the 3D Seismic Symposium on March 6th in Denver
What is the "holy grail" of Machine Learning in seismic interpretation? by Dr. Tom Smith, GSH Luncheon 2018
Using Attributes to Interpret the Environment of Deposition - A Video Course. Taught by Kurt Marfurt, Rocky Roden, and ChingWen Chen

Acceleration of Phase

Attribute Description:  This measures the rate of change for instantaneous phase

Interpretation Use:  This attribute may provide value by

  • Accentuating bedding differences
  • Higher Resolution may have a higher noise level due to differentiation
  • May reflect some elastic properties of resolvable beds

Recommended Colorbar:

Since the distribution of this data is gaussian with spikes at the extremes, a normal seismic colorbar can be used to visualize this attribute – it will show a contrast between “Peaks” and “Troughs” and highlight them against the central data.   A phase colorbar with common colors at peak and trough zones can also be used and will emphasize the central data more.

In this example, we are using a black – white – red colorbar.

  Colorbar and amplitude spectrum of Acceleration of Phase

Colorbar and amplitude spectrum of Acceleration of Phase

Note that a phase based colorbar could also be used.

Example:

 Vertical display of Acceleration of Phase

Vertical display of Acceleration of Phase

 Time slice of Acceleration of Phase

Time slice of Acceleration of Phase

 Frequency Spectrum

Frequency Spectrum

Computation:  Acceleration of Phase (cycles/sec/sec) is based on instantaneous acceleration. The time derivative of instantaneous frequency/wavenumber, by definition, gives the instantaneous acceleration. This can be computed both from instantaneous frequency/wavenumber and from time averaged instantaneous frequency/wavenumber. It is obvious that the time derivative of instantaneous frequency/wavenumber will accentuate the local frequency/wavenumber jumps, and hence will make the thin bed indicators more prominent. It should also indicate to some degree the effect of absorption by showing the frequency/wavenumber dispersion of seismic signals going through unconsolidated or quickly deposited layers:

Acceleration of Phase - 5.png

The corresponding value in depth domain is calculated as the second derivative of phase with respect to depth:

Acceleration of Phase - 6.png

References:

  • Chopra, S. and K. J. Marfurt, 2007, Seismic attributes for prospect identification and reservoir characterization:  Society of Exploration Geophysicists, Geophysical Developments #11.
  • Taner, M. T., 2001, Seismic attributes:  Canadian Society of Exploration Geophysicists Recorder, 26, no 7.