Extracting Polar Anisotropy Parameters from Seismic Data

With Vp, Vs, and density well logs, we can do isotropic AVO forward modeling, using isotropic Zoeppritz equations or its approximations, and a wavelet extracted from the seismic data, to get synthetic seismic data. Compared with real seismic data, these synthetic data are scaled differently, and ignore many propagation effects. Conventionally, the seismic data are normalized to the isotropic synthetic data for comparison; this procedure suppresses the anisotropy information in the real data. In this study, I tested a new method, using log data of Vp, Vs, and density, together with seismic pre-stack Common Depth Point (CDP) gathers near the well site, to deduce anisotropy parameters from them. This dataset is from Colony Sand, Alberta, Canada. I calculated the normalization function, as in the conventional procedure, but then filtered it in frequency domain using a cut-off frequency to be determined empirically. The low-frequency part of the normalization function was used to eliminate the propagation factors in the real data, but not the reflection coefficients. After scaling, the difference between the real data, thus normalized, and the isotropic synthetic data are attributed to the anisotropic part of the reflection coefficients. The resulting distributions of and are compared to the gamma-ray log. There is a positive correlation between the anisotropy parameter and the gamma-ray log, which is an indication of the validity of the method.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Geophysics

Grantor

University of Houston

Year dc:date.issued

2013

Author dc:creator

• Lin, Rongrong 1989-

Advisors dc:contributor.advisor

• Stewart, Robert R.
• Thomsen, Leon

Committee members dc:contributor.committeemember

• Castagna, John P.
• Ebrom, Daniel A.

• Anisotropy
• AVO

Statement dc:rights

• The author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/10657/3288

OAI identifier oai:identifier

oai:uh-ir.tdl.org:10657/3288