Any course that did not reach minimum enrollment by 8 September was canceled. Only on-site registration was available after 6 October on a first-come, first-serve basis. Due to class size limitations, on-site registration the day of the course was not guaranteed! Friday, 15 October 2010
2010 SEG/EAGE Distinguished Instructor Short Course (DISC)
Hyatt Regency Denver
Geophysics Under Stress: Geomechanical Applications of Seismic and Borehole Acoustic Waves
By Colin M. Sayers, Schlumberger click headers below to read more
The state of stress within the earth has a profound effect on the propagation of seismic and borehole acoustic waves, this leads to many important applications of elastic waves for solving problems in petroleum geomechanics. The purpose of this course was to provide an overview of the sensitivity of elastic waves in the earth to the in-situ stress, pore pressure, and anisotropy of the rock fabric resulting from the depositional and stress history of the rock, and to introduce some of the applications of this sensitivity. The course provided the basis for applying geophysics and rock physics solutions to geomechanical challenges in exploration, drilling, and production. A variety of applications and real data examples were presented, particular emphasis was placed on the rock physics basis underlying the use of geophysical data for solving geomechanical problems.
The following topics were addressed in the course:
- Introduction to the effects of stress in the earth. Why pore pressure, in-situ stress and geomechanical properties are important.
- Sediment compaction and the state of stress in the earth. Vertical stress, pore pressure and sediment compaction. Horizontal stress in a relaxed basin. Estimation of the minimum and the maximum horizontal stress. Tectonic strains.
- Pore pressure. Velocity vs. effective stress relations. Pore pressure estimation from velocity. Clay diagenesis. Unloading. The need for fit-for-purpose seismic velocities. Uncertainty analysis. Combining seismic velocities with well velocities for improved pore pressure estimation. Dipping layers and lateral pore pressure transfer.
- Stress sensitivity of sandstones. Third-order elasticity theory. Dependence of elastic wave velocities on porosity in sandstones. The importance of compliant grain boundaries, microcracks and fractures on velocities in sandstones. The use of elastic waves to monitor stress-induced damage.
- Wellbore stability and wave velocities near a borehole. Stress changes in the vicinity of a borehole. Mechanical behavior of rock in the vicinity of a borehole. Stress dependence of elastic wave velocities. Linearized expressions for the change in velocity for small changes in stress
- Reservoir geomechanics and 4D seismic monitoring. Reservoir stress path. The effect of stress path on rock deformation and failure. Rock failure. Monitoring reservoir stress changes using time-lapse seismic. The difference in reservoir stress path between injection and depletion.
- Fractured reservoirs. Effects of fractures on seismic waves. Multiple fracture sets. Amplitude Versus Offset and Azimuth (AVOA). Simplifications for weak anisotropy. Effects of inequality between the normal and shear compliance of fractures. Microstructural models of fracture compliance.
- The seismic anisotropy of shales. The relation of shale anisotropy to microstructure. The effect of interparticle regions on seismic anisotropy. Clay mineral anisotropy. Effect of disorder in the orientation of clay particles. The static elastic moduli for a TI medium and the implications for hydraulic fracture containment.
Who Should Attend?
The integrated nature of this course means that it is suitable for individuals from all subsurface disciplines including geophysics, geomechanics, rock physics, petrophysics, geology, geomodeling, and drilling, reservoir, and petroleum engineering. The short-course presentation, limited to one-day, provided an overview of the basic concepts and applications, and minimizes the use of mathematical developments. As a result, the course presentation did not require a theoretical background and could be attended by a broad section of working geoscientists and engineers interested in applying geophysical data to the solution of geomechanical problems. The course book provided support for the course, and further extend some of the more technical considerations.
For more information about the 2010 SEG/EAGE DISC, contact:
Jill Abbott at the SEG Business Office • Phone: +1.918.497.5589 • Fax: +1.918.497.5557 • E-mail: DISC@seg.org
Saturday–Sunday, 16-17 October 2010
Continuing Education Courses
Colorado Convention Center
Seismic Data Processing
- Processing, Inversion and Reconstruction of Seismic Data by Mauricio Sacchi
- Applications of Geophysical Inversion and Imaging by Brian Russell and Larry Lines
- Seismic Anisotropy: Basic Theory & Applications in Exploration & Reservoir Characterization by Ilya Tsvankin
- Digital Signal Analysis in Seismic Data Processing by Enders Robinson and Osman Hassan
Seismic Data Interpretation
- Petroleum Systems of Deepwater Settings by Paul Weimer
Potential Fields/ Non-Seismic
- Gravity and Magnetics for Explorationists by Michal Ruder
Exploration & Production Geophysics
- Borehole Geophysics: Theory and Practice by Ronald Hinds and Richard Kuzmiski
- 3D Seismic Attributes for Prospect Identification & Reservoir Characterization by Kurt Marfurt
- Multi-Component Seismic, Principles and Applications by Robert Garotta
Seismic Data Acquisition
- 3D Seismic Data Acquisition: An Update on Modern Technologies and Usage Methodologies by Malcolm Lansley
- Near-Surface Seismology by Gregory S. Baker