Elastic-Wave Imaging Using P-P, Sh-Sh, and Sv-P Events: Modeling and Data Processing

This thesis focuses on using seismic data that were generated by a vertical vibrator and recorded by a vertical geophone to build two different subsurface images: a conventional P-P section and a converted-wave SV-P section. Radiation patterns are calculated based on Miller and Pursey’s equations that show P- and S-wave radiation from a vertical point source. Elastic modeling is performed for simple models to study the P- and S-wave modes propagating within the medium and to test the effectiveness of an SV-P processing flow. This special flow is designed to carefully attenuate noise and P-P signal while keeping the low-frequency SV-P signal intact. The processing builds separate P-P and SV-P subsurface images. The original vertical-vertical and an additional pure shear (SH-SH) datasets were processed to obtain 2000 m P-P, 350 m SV-P, and 500 m SH-SH depth images, their corresponding velocity fields, and Vp/Vs values (Vp/Vs=6 on average). The resulting images are tied to the interpreted shallow 140 m well logs for quality control of the data processing and compared. The P-P and SH-SH images tie well with the conductivity logs and accurately show the targeted shallow sand intervals. The SV-P image features similar reflectors as the P-P and SH-SH images. These SV-P events, although less continuous, provide subsurface information down to about 300 m depth and have better resolution in the shallow part of the image compared to the P-P image. Despite several drawbacks of this method, there is promise in SV-P extraction and imaging especially for shallow targets with all of the benefits of the converted-wave seismic 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

2017

Author dc:creator

• Ermolaeva, Elena 1988-

Advisor dc:contributor.advisor

• Sager, William W.

Committee members dc:contributor.committeemember

• Stewart, Robert R.
• Hardage, Bob A.
• Hilterman, Fred J.

• Seismic
• Processing
• Multicomponent
• Converted
• Imaging

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/10657/2660

OAI identifier oai:identifier

oai:uh-ir.tdl.org:10657/2660