The course is recommended for geophysicists with an undergraduate background who are involved with seismic acquisition, processing or interpretation.
This course provides an overview of converted-wave (PS-wave) prestack migration and joint AVO/A inversion from characterizing the overburden to petrophysical analysis of the reservoir. Fundamentals of elastic wavefields and shear-wave velocities are discussed to introduce the properties of PS-wave illumination, resolution, and azimuthal anisotropy. Numerous examples and case histories show the application of various 3D prestack migration and inversion techniques. Both land and marine surveys are highlighted to demonstrate the full range of petrophysical applications: large scale structure, lithology, and reservoir fluid properties.
Duration
Two days
Intended Audience
Intermediate level
Prerequisites (Knowledge/Experience/Education Required)
The course is recommended for geophysicists with an undergraduate background who are involved with seismic acquisition, processing or interpretation.
Topics discussed in this course include
- Elastic wavefield properties
- Rock properties, logs, and VSP
- P and S velocity and density
- P- and PS-wave synthetics
- Basic 3D PS-wave acquisition
- Sources, receivers, radiation, and scattering properties
- Survey designs, recording systems
- P- and PS-wave pre-processing
- Statics, velocity model building
- Prestack migration, joint AVO/A inversion
- Anisotropy and S-wave splitting considerations
- PS-wave petrophysical applications
- Structure (thickness, pinchouts, faults)
- Lithology (stratigraphy, facies, TOC)
- Porosity and fluid properties (phase, saturation, pressure)
- Fractures (stress, geomechanics)
- Time-lapse monitoring
Learner Outcomes
- Explain the basics of PS-waves: time registration with P-waves, S-wave splitting, VP/VS analyses, and velocities.
- Define elastodynamic processes that generate converted waves and how they relate to AVO/Az elastic rock properties.
- Illustrate characteristics of PS-wave asymmetry and subsurface illumination.
- Describe unique characteristics of 3D PS-wave prestack migration: polarization, VTI anisotropy, fast and slow PS-waves, and variations with azimuth.
- Examine petrophysical applications: elastic impedance inversion, imaging through gas, fracture/stress characterization, and timelapse.