Instructor: Mr. Etienne Robein (ERT, Pau, France)
Duration
2 Days
Discipline
Geophysics - Surface Imaging
Level
Intermediate
CPD Points
10
A short version of this course has been recorded as an E-Lecture. Watching this video will give you a clear introduction of what the course is about and it will help you to prepare yourself if you are going to attend it!
As the search for new resources forces to maximize the production of discovered reservoirs and explore new ones in domains that are increasingly complex, seismic imaging is becoming more and more important.
Seismic imaging is inherent part of the data processing sequence that aims to produce clear and accurate images of the Earth's subsurface suitable for interpretation by geoscientists.
This course will provide the audience with a unified overview of today's most popular seismic depth imaging techniques used in the oil and gas industry. These requires an estimate of how fast the seismic waves travel at any given point in the Earth and at any direction (anisotropy): the velocity model. Recent advances in seismic acquisition, imaging technology and high-performance computing allow us to correctly assess a much greater complexity of subsurface models and consequently, improve the accuracy of seismic images and detect structures that were previously invisible.
The course will present in simple terms (cartoons rather than equations!) the principle of different techniques in each class of methods (Kirchhoff, Beam Migrations, WEM, RTM), while pointing out their respective merits and limitations. Similarities and differences between time- and depth-imaging will be briefly reviewed. Special emphasis will be on methods used to build the necessary anisotropic velocity models. Both ray-based techniques (linear and non-linear tomography) and wavefield extrapolation-based ones, including full-waveform inversion, will be addressed.
The relationship between recent developments in acquisition and imaging on the one hand and interpretation and imaging on the other will also be stressed.
Reminders
Ray-based Kirchhoff Depth Migrations (KPreSDM)
Time processing: Kirchhoff migration in ‘vertical time’ (PreSTM)
The various Beam Migrations
Velocity Model Building (VMB) by Ray-based tomography
Wavefield extrapolation-based methods: WEM and RTM
Conclusion
The course can be understood by geoscientists with a moderate mathematical background. Physical concepts are presented without equations but with a maximum of simple schemes and animated graphic illustrations. However, some basic knowledge of wave propagation theory may help. A comprehensive list of references is given in the book and updated in the presentation for those who are interested in more rigorous and mathematical approaches.
The course is aimed at geoscientists involved in exploration and production projects where seismic play a role and who wish to:
The course will also benefit students who want to have a first acquaintance to reflection seismic in general and seismic imaging in particular.
Etienne is the author or co-author of several presentations in International Conferences, including the SEG, EAGE, WPC, AAPG, and Petroleum Geology Conference and he contributed to the EAGE’s “Distinguished Lecture Programme” and “Education days”. In 2003, he published a text book on “Velocities, Time-imaging and Depth-imaging in Reflection Seismics,” which became a best-seller EAGE Edition. Etienne was President of EAGE in 2000. He was also Chairman of EAGE’s Research Committee, member of the EAGE Awards Committee and Europe’s representative at the SEG Council.