Applications of Seismic Anisotropy in the Oil and Gas Industry

Instructor: Dr. Vladimir Grechka (Marathon Oil Corporation, Texas, United States)

Course description

Elastic anisotropy can strongly influence seismic data. This course discusses modeling, inversion and processing of seismic reflection and VSP data in the presence of anisotropy. The most critical step in extending the existing processing techniques to anisotropic media is to identify and estimate the medium parameters responsible for measured seismic signatures. The course emphasizes these parameters for vertical transverse isotropy – the anisotropic model usually associated with shales. Field-data examples illustrate the improvements in imaging achieved by anisotropic migration algorithms and the possibility of using anisotropy for lithology discrimination and fracture characterization.

Course objectives

When the course is completed, students will have a clear understanding of the following:

• Seismic anisotropy is a real feature of the subsurface. It is caused by a number factors (e.g., lithology, fractures, fine layering) that can be quantified, leading to a better characterization of the subsurface.
  
• Any attempt of extracting more information from seismic data necessitates taking anisotropy into account.
  
• There exist established techniques for estimating anisotropy from seismic data. 
  

Course outline

• Definition, importance, and physical causes of seismic anisotropy
  
• Plane waves and rays in anisotropic media
  
• Thomsen parameters
  
• NMO velocity
  
• Nonhyperbolic moveout
  
• Velocity model building and imaging
  
• Fracture characterization
  
• Anisotropic velocity-model building for downhole microseismic 
  

Participants' profile

Geophysicists who wish to enhance their understanding of the subsurface and learn about modern techniques for extracting more information from seismic data.

Vladimir Grechka received his MS degree (1984) in geophysical exploration from Novosibirsk State University, Russia, and a PhD (1990) in geophysics from the Institute of Geophysics, Novosibirsk, Russia. He worked in the same Institute from 1984 to 1994 as a Research Scientist. He was a graduate student at the University of Texas at Dallas from 1994 to 1995. 

Then Vladimir joined the Department of Geophysics, Colorado School of Mines, where he was an Associate Research Professor and a co-leader of the Center for Wave Phenomena. From 2001 to 2012 he worked as a Senior Geophysicist at Shell Exploration & Production company. 

Currently, Vladimir is a Geoscience Consultant with Marathon Oil Company.Vladimir's research is focused on theory of seismic wave propagation in anisotropic media, velocity analysis, fracture characterization, and microseismic. Vladimir received J. Clarence Karcher Award from the SEG in 1997 and the East European Award from the European Geophysical Society in 1992. He served as the Editor-in-Chief of Geophysics from 2009 to 2011. Vladimir is a member of the SEG and EAGE