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
Dr. Kurt Marfurt and Dr. Tom Smith featured in the July edition of AOGR on Machine Learning and Multi-Attribute Analysis
Rocky Roden and Ching Wen Chen in May edition of First Break - Interpretation of DHI Characteristics using Machine Learning

Normalized Amplitude

Normalized Amplitude is computed as the cosine of instantaneous phase angle. This attribute has all of the details of instantaneous phase while avoiding the jumps inherent in it. The attribute has no amplitude information and its values vary between –1 and +1.

  Here is a display of amplitude a(t) ,  normalized amplitude ā(t) and phase φ(t) to illustrate that normalized amplitude is much closer to phase than it is to amplitude.

Here is a display of amplitude a(t)normalized amplitude ā(t) and phase φ(t) to illustrate that normalized amplitude is much closer to phase than it is to amplitude.

Interpretation Use:

  • It represents continuity and is helpful in lateral continuity direction determination.  
  • It will have no amplitude information

Recommended Colorbar:

This attribute has most of its values at +1 and -1 and as mentioned does not contain the original amplitude information.  Colorbars that emphasize the endpoints and the zero-crossing line work best for this attribute similar to some of the edge detection attributes.

  Example colorbar and amplitude spectrum

Example colorbar and amplitude spectrum

Example: 

 Vertical display of Normalized Amplitude

Vertical display of Normalized Amplitude

 Time slice of Normalized Amplitude

Time slice of Normalized Amplitude

 Frequency Spectrum

Frequency Spectrum

Computation:
Normalized Amplitude is computed as the cosine of instantaneous phase angle:

Noramlized Amplitude - 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.