Oil and Gas
Oil and Gas | Geophysics and Seismic Interpretation
This course is for seismic interpreters and data processors seeking to gain a practical understanding of the current commercial methods of seismic imaging with an emphasis on full azimuth imaging. Participants will receive the knowledge required to make informed decisions regarding which processing and imaging algorithms to use, how to build and update velocity models, and learn to effectively design, guide, and quality control full-azimuth, full-offset imaging projects in a variety of geological settings. Participants will learn methodologies to compute, quality control and incorporate azimuthal seismic attributes with isotropic seismic attributes and reservoir information.
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Schedule
Duration and Training Method
This is a four-day classroom course using a combination of lectures, demonstrations, case histories, and hands-on practical work exercises.
Course Overview
Learning Outcomes
Participants will learn to:
- Distinguish the fundamental differences between time and depth migration.
- Differentiate between commonly used imaging algorithms including ray and wave-equation techniques.
- Understand current marine and land acquisition techniques used for wide/full azimuth imaging.
- Understand current processing and imaging strategies to obtain desired products for conventional and resource plays.
- Monitor the data conditioning stages of the initial processing sequence.
- Provide the appropriate interpretation inputs to the velocity model building process, and verify that the form of the velocity model is appropriate for the geology of the project.
- Understand the benefits, as well as the technical challenges, presented by full-azimuth, full-offset 3D data sets. Special emphasis will be placed on the conditioning of data to obtain, and the computation, uncertainty and use of, azimuthal interval velocity and azimuthal amplitude information.
- Incorporate seismic/well tie information that can be used as a constraint for velocity modeling and the determination of anisotropy parameters.
- Prepare and QC post-imaging data for isotropic and azimuthal simultaneous inversions.
Course Content
The course content is divided into 8 chapters. On the last day, time will be provided for an open forum discussion of several client projects and case histories. Participants are encouraged to bring data examples to the class for general discussion.
Chapter 1: Introduction and the Reflection Seismic Experiment
Chapter 2: Full/wide Azimuth Seismic Background
- Marine, land and ocean bottom acquisition
- Simultaneous source shooting
Chapter 3. Basics of Seismic Imaging
- What is migration?
- Ray theoretical time-to-depth conversion
- Zero-offset time migration
- Zero-offset depth migration
- Imaging principles for zero-offset migration
- Image sensitivity to migration velocity
- Migration artifacts
Chapter 4. Data Conditioning with Emphasis on Wide Azimuth Processes
- Improving resolution
- Seismic datums
- Initial velocity analysis
- Refraction/reflection statics
- Multiple identification and suppression
Chapter 5. 3D Migration/Imaging
- Depth migration vs. time migration - background
- Depth migration vs. time migration - examples
- Pre-stack migration imaging principles
- Data acquisition considerations
- Data organization and binning for azimuthal imaging
- Use of 5-D interpolation
- Choosing an algorithm
- Migration parameterization, testing and quality control
Chapter 6. Migration Velocity Analysis and Velocity Model Updating
- Building an initial migration velocity field
- Basic concepts of MVA
- Tomographic velocity model parameterization and updating
- Estimating and incorporating layer anisotropy
- Estimating and incorporating azimuthal anisotropy
- Full-waveform inversion
- Salt flooding
- Velocity and image uncertainty
Chapter 7: Post-imaging Analysis
- Interpretation in time vs. depth
- Post-imaging time-depth conversion
- Incorporating other seismic attributes
- Co-rendering azimuthal and isotropic attributes
- Off set and refl ection-angle common-image-point gathers
- Preparation and QC of pre-stack migrated data for simultaneous inversions
Chapter 8: Case Histories
- Land
- Marine
- Ocean-bottom seismic
- Simultaneous sources
Who Should Attend and Prerequisites
This course should be of interest to all seismic interpreters and data processors planning to incorporate depth imaging into their exploration and/or exploitation projects. Resource plays and sub-salt reservoirs present special imaging challenges that are addressed in this course.
Instructors
Walt Lynn
Background
Subsequent to finishing his degrees, Walt has spent his career in the seismic service sector of the oil and gas industry – 11 years with Western Geophysical, 11 years with Petroleum Geo-services, PGS and has been a consultant with Lynn Inc. since 2002. He has held geophysical positions within R&D groups, has managed R&D divisions, and has run operations for worldwide data processing.
Walt specializes in multi-azimuth, multi-component 3-D seismic acquisition, processing and interpretation and an Adjunct Associate Professor at the Colorado School of Mines. Walt is a Past-President (2001-02) and an Honorary Member of the Society of Exploration Geophysicists and an Honorary member of Geophysical Society of Houston.
Affiliations and Accreditation
PhD Stanford University - Geophysics
MSc Oregon State University - Geophysics
BSc Princeton University - Geology and Geophysics (High Honors)
Near-Surface Geophysicists, European Association of Geoscientists and Engineers
Honorary Societies Sigma Xi, Phi Kappa Phi
The Russian Academy of Natural Sciences
Courses Taught
N282: Introduction to Full Azimuth Imaging for Conventional Plays and Resource Plays