Course Format

This course is part of the EAGE Education Tours (EET), the flagship education programme of the Association. EET courses are specifically designed to bring members the latest developments in geoscience and engineering through experienced instructors from industry and academia. In 2020 we are proud to introduce EET courses that can be attended remotely over two half-day sessions. Participants will have the possibility to interact live with the instructor and ask questions. EET courses are supported by the EAGE Education Fund for the benefit of members, who can register for special discounted fees.. 

Education Packages

To help you save on registration fees and better organize your learning path, we are offering Education Packages for all Interactive Online Short Courses and Online EETs. The packages are valid for a period of 12 months, choose between packages of 3, 5 and 10 credits. 

Course Description

I. Wavefield Data Analysis Time images usually provide sufficient information for a variety of subsurface models of moderate complexity and facilitate the estimation of the model for depth migration. Improving the quality of time sections remains the focus of intensive research. In particular, a lot of efforts are directed towards improving the accuracy of moveout correction. The proposed course discusses time imaging procedures such as Multifocusing and Common Reflection Surface when each image trace is constructed by stacking traces which need not belong to the same CMP gather. In this case a new and more general moveout correction is requested. These new methods open a way for reliable wavefield analysis and wavefront parameters estimation. The latest represents a basis for different applications including signal enhancement, velocity model building, statics correction, AVO analysis. 

 II. Seismic Diffraction Currently applied seismic processing and imaging are almost exclusively based on seismic reflection. The latest is the response to continuity in the subsurface. At the same time accurate and reliable imaging of small scale geological elements and discontinuities of the subsurface such as faults, unconformity, fractures etc. are a key to improve seismic resolution. In unconventional reservoirs the main objective is detection of fracture corridors. Small scale objects give rise to a diffraction response. Use of seismic diffraction is a rapidly emerging technology which has tremendous potential to reduce exploration and production risks and increase oil and gas recovery. The course integrates elements of the theory of wave propagation, diffraction modeling and imaging, and interpretation. The main objectives are: understanding the role of small and medium scale subsurface objects and elements in forming the total seismic wavefield and using diffraction for imaging. 

 III. Imaging without precise knowledge of the subsurface velocity model In the proposed course I introduce a way to look at model-independent seismic imaging using the quantum mechanics concept. Can Feynman’s path-integral idea be used for seismic imaging? We can construct the seismic image by summation over the contributions of elementary signals propagated along a representative sample of possible paths between the source and receiver points. When the velocity model is estimated with uncertainties, a single stationary path does not produce a correctly focused subsurface image. In contrary, quantum imaging uses all possible trajectories accounts for multiple stationary paths and takes into account model uncertainties. 

 IV. Pitfalls and challenges of seismic inversion Proposed solutions are usually based on the criterion of the best fit between calculated and observed data. But it is well understood that by itself, a good fit does not guarantee that an inverted model is correct. Seismic inversion may lead to construction of several subsurface models with significantly different geological meaning, all of which fit the observed data equally well. The ill-posedness of seismic inverse problems is fundamental and does not depend on a particular type of algorithm or on the approach underlying the algorithms. In this course, I formulate a number of fundamental questions which should be addressed to make the inverse problems a mature science rather than a set of recipes. 

 V. Time Reversal in Seismic Time Reversal (TR) plays an important role in seismic. It is directly connected to reverse time migration, interferometry and virtual source methods. Recently time reversal is proposed to localize subsurface sources in passive seismic and scatterers in active seismic surveys. Unlike in conventional migration, time reversal approach, in principle, does not require application of imaging condition. Numerical implementation of the time reversal method uses back propagation of the time-reversed recorded wavefield followed by an analysis of its obtained focusing. The physical implementation of TR, called Time Reversal Mirror (TRM), is used in various applications: underwater acoustics, telecommunication, cancer therapy, lithotripsy, nondestructive testing, etc. I demonstrate physical implementation of the TRM in seismic. Results of the field experiment show very promising results. I discuss possible applications of the method in seismic exploration and production.