Applied Geological Subsurface Imaging and Velocity Model Building Training

Applied Geological Subsurface Imaging and Velocity Model Building Training Course

Velocity is one of the most important parameter that can be derived from the seismic data. Velocity values are indicative for layer identification and thus convey rock properties. Moreover, velocities relate the seismic measurements that are in (two-way) traveltime to the end product of seismic data processing, i.e. the depth picture of the subsurface that can be obtained via migration or seismic imaging. New developments in acquisition geometries enable the determination of velocities with greater accuracy and also require to take into account anisotropy. The relationships between elastic constants and velocities are explained; this includes the phenomenon of anisotropy. In the end it is the wave equation that describes all wave propagation phenomena. Different types of velocities play a role during the processing sequence; stacking and migration being the most important ones. Migration or seismic imaging is the typical end product of conventional seismic data processing. The process of migration, whereby a proper image in time or depth of the subsurface is obtained, is directly related with the velocity model that both serves as input for the migration process as well as is the result of such a migration. Therefore migration and velocity model building are intimately related processes. DMO (dip moveout) can be considered as an intermediate process; it contains elements of migration and can be used in velocity model building. The implementation of migration is characterized by a multitude of methods and algorithms; there is also a variety of methods to build a velocity model. By the same token there is a number of DMO algorithms. This course gives an overview of all aspects of velocity that one encounters during seismic data processing, of the migration principles, methods and algorithms, of the velocity model building principles and methods as well as of the different DMO algorithms. In addition VSP data acquisition and processing will be discussed. During the course and at the end a number of representative case studies and examples will be shown to illustrate the material covered during this course.

Participants will get a full understanding and appreciation of the different types of velocity and corresponding methods for their measurement, especially interval velocities and their relationship with rock properties and prestack depth migration. They will become familiar with the different methods of migration and their subsequent implementation. They will be able to judge the strong and weak points of each algorithm and they can select their proper parameters. They can select and apply the method that is most appropriate for velocity model building based on the data, pre-processing results, geological information and stated objectives.

Geophysicists – processing and interpretation –, geologists, and petrophysicists who need to understand how the various types of velocity information can be derived from seismic data and who need to understand how subsurface images are generated.

As the material covers all theory in association with present day practicalities made possible by new developments, this course is relevant for those who are fresh from the university as well for those who like to be updated on the newest developments.

Continuing Professional Development

35 HOURS CPD