Seismic Velocities and Depth Conversion - SVDC
Posted by PetroSkills on Thursday, March 18, 2010
Start Date Monday, May 17, 2010
End Date Friday, May 21, 2010
Location
London, UK
Full Details
See full details at http://www.petroskills.com/courseDetails.aspx?courseID=809
DESIGNED FOR
Geoscientists and engineers, especially seismic interpreters. Anyone involved in using seismic data who needs to understand the theory and proceedures for creating velocity models and converting seismic data from time to depth.
YOU WILL LEARN HOW TO
Understand the various types of velocities, their calculation, and the validity of their interpolation and extrapolation
Compare, quality control, smooth, and combine the various velocity types into an integrated velocity model
Validate model quality by examining the changes in velocity needed to tie the seismic data to depth
Use the model to convert horizons, faults, and seismic data from time to depth
Learn how velocity models are used for other studies such as forward modeling and pore-pressure prediction.
ABOUT THE COURSE
Seismic data is acquired in time – the time taken for the sound to travel from the source to reflectors and to return to receivers. However wells are drilled in depth, not time, and variations in velocity can distort the size and shape of possible reservoirs. Therefore conversion from time to depth is needed for a clear picture of the prospect and the risks involved.
This course will teach you how to use velocity information and structural inputs to build a consistent velocity model. First all input velocity data must be quality controlled and a calibrated velocity model created. Then the model is used to convert time horizons and seismic time data to depth. Both pre-stack and post-stack migrated data are considered. The course also covers some of the velocity problems encountered the more widely available depth-migrated data.
Each section of the course is supported with in-class exercises. Each student is provided with a USB flash drive (memory stick) that contains the exercises and the data and software needed for the exercises. The flash drive also contains all of the course slides. The class requires the use of a windows PC laptop or workstation for every student or every two students.
As a foundataion class, the instruction starts with the basics and proceeds to more advanced topics. The student should have a basic understanding of geophysics such as offered in PetroSkills’ Basic Geophysics course. No advanced math is used, but algebra and lots of diagrams are used to explain the needed concepts.
COURSE CONTENT
Velocity: definition and comparison of the many types of velocity including average, interval, RMS, stacking, migration, pressure-wave, and shear-wave.
Velocity Inputs: Accuracy and regional extent of each, including check shots, VSPs, sonic logs, time/depth functions, well picks and pseudo velocities, seismic velocities, and horizons for structural control
Synthetic Seismograms: creation, upscaling, and tie to seismic. Advanced synthetics including synthetic gather creation, Zoeppritz’s equations, AVA, and AVO
Matching Synthetics: VSPs and seismic data tied to synthetics
Seismic Velocities: semblance, picking, multiples
Migration and Migration Velocities: theory and applications, pre- and post-stack algorithms, tomography, and iterative velocity analysis
Velocity Model Building: workflows to integrate stacking velocities, time/depth curves, well picks associated with seismic horizons (pseudo-velocities), and structure from horizons. Geostatistics can be added.
Time to Depth Conversions: vertical stretch, inverse raytracing, migration, and other methodologies
Advanced Topics: forward modeling, pore pressure prediction, anisotropy, and geostatistics
See full details at http://www.petroskills.com/courseDetails.aspx?courseID=809
Category
Training Courses