Elasticwave surface reflections were also used by bostock et al. Oil and gas exploration is a costly and risky business. Geophysical imaging also known as geophysical tomography is a minimally destructive geophysical technique that investigates the subsurface of a terrestrial planet. Such non hyperbolic event will not be properly imaged if poststack seismic imaging methods are applied biondi, 2006. In seplib3d, to describe the irregular data geometry, we associate each seismic trace with a trace header, as. Seismic imaging technology seismic imaging is considered key to reduce risk and cost in exploratory as well as development drilling. Conventional processing and imaging methods will fail in case of facing complex media, strong heterogeneity and poor quality data. Biondi 2006 for more details on seismic data acquisition and processing.
Mathematics of seismic imaging part i rice university. Seismic imaging of subsurface geology training course. They transform surfacerelated multiples into primaries with the sources at the surface reflection points. These distributions can be used to understand the subsurface geology and locate deposits of oil and gas. Seismic modeling of complex geological structures intechopen. Reflection seismic imaging using artificial sources is a well elaborated and widely used approach e. The technology allows explorers and drillers with more pinpoint accuracy that goes to should deliver better production and and a slightly longer well life. Cgg seismic imaging analyst interview questions glassdoor. It relates the different models of seismic propagation, reflection, and imaging providing links to reflectivitybased imaging and to nonlinear seismic inversion.
However, because the reader is likely to be familiar and comfortable already with 2d processing methods, whenever useful i discuss the connections between 3d algorithms and the corresponding 2d algorithms. Free interview details posted anonymously by cgg interview candidates. The book coherently presents the main components of seismic imaging dataacquisition geometry, migration, and velocity estimation by exposing. How 3d seismic imaging revolutionized the drilling industry.
Study on the limitations of traveltime inversion applied to. Apply to software engineer, researcher, analyst and more. Seismic imaging web site other useful business software mongodb is a general purpose, documentbased, distributed database built for modern application developers and for the cloud era. The book coherently presents the main components of seismic imaging dataacquisition geometry, migration, and velocity estimationby. Seismic imaging algorithms can be divided in two broad categories. However, in recent years the passive seismic tomography has emerged as a solution to the problem. Seismic imaging directs an intense sound source into the ground to evaluate subsurface conditions and to possibly detect high concentrations of contamination. Following biondi 2007 figure 6 shows the main reasons why 2d. Basics of seismic imaging center for subsurface imaging.
Impedance equals density times the interval velocity. Seismic migration using focused gaussian beams is applied for the inversion of commonshot re. The primary objective of this course is to provide a broad and intuitive understanding of seismic imaging concepts and methods that enables geoscientists to make the appropriate decisions during acquisition, processing, imaging, and interpretation projects. By studying the echoes, petroleum geologists seek to calculate the depth and. Reverse time migration rtm is an imaging technique that was introduced. Nmo velocity analysis fourth order nmo the velocities are checked interactively with nmo corrected gathers, stacks and isovelocity plots.
Receivers called geophones, analogous to microphones, pick up echoes that come back up through the ground and record the intensity and time of the echo on computers. Seismic image issues are very challenging in thrust fold areas, specially in highly undulated terrain. Biondi seismic images are crucial to todays exploration and reservoir monitoring. Seismic imaging and illumination with internal multiples article in geophysical journal international 1763. This is particularly true in challenging areas such as in deep water and when drilling beneath salt and. The sdcard containing the incremental update file only needs to be inserted on the master mfd the slave mfds and the nn3d components will be updated over. The seismic profiles, not previously shown publicly, provide new information about. Subbasalt imaging is very sensitive to acquisition and processing parameters.
An example system applies global consistency constraints during iterative volume dip estimation of a seismic volume to improve upon conventional dip estimation methods. Gray2, and yu zhang3 abstract prestack depth migration is the most glamorous step of seismic processing because it transforms mere data into an image, and that image is considered to be an accurate structuraldescriptionoftheearth. Industrys seismic imaging methods share one fundamental assumption. Welcome to slim seismic laboratory for imaging and modeling. Seismic imaging and illumination with internal multiples. Earths interior seismic evidence explanation duration. The book coherently presents the main components of seismic imaging dataacquisition geometry, migration, and velocity estimation by exposing the links. One might think of microseismic events as sources for reflection imaging. Biondi is in close contact with the practical applications of seismic imaging by his involvement with 3dgeo development that he cofounded in 1994. The two seismic profiles were reprocessed to improve the reflectivity in the shallow part of the section and imaging of dipping reflectors. We also understand that when dealing with 3d or 2d depth imaging, manual rms analysis improves the stability of seeding the initial interval velocities of tomographic analysis. He taught segs first course in dipmoveout processing as part of the continuing education program, and was editor of dmo processing, volume 16. Overview and classification of wavefield seismic imaging methods. Seismic imaging customized solutions for every imaging objective.
Seismic imaging of evaporite bodies is notoriously difficult due to the complex shapes of. Seismic imaging in complex geological structures is state of art to deliver a high quality section for further geological interpretation. Probably, the most prominent method of the subsurface imaging hinges upon the surface recordings of the seismic energy seismic imaging biondi, 2006. In acquisition, long offset 2d and 3d seismic data can contribute to an improvement in the seismic image below top basalt. He also received segs awards for best paper in geophysics in 1992 imaging salt with seismic turning waves and best paper presented at the annual meeting in 2002 atomic meshing of seismic images. At the same time, subsurface imaging is a crucial part of analyzing the geological structures and provides the means for remote studying of the earths properties. The main contribution to the image, as shown in the figure to the right, are reflected waves. Physical seismic modeling of a nearvertical fault zone. Concepts and applications in 3d seismic imaging, by biondo biondi is based on the segeage distinguished instructor series course no. Introduction to seismic imaging alison malcolm department of earth, atmospheric and planetary sciences mit august 20, 2010.
Systems and methods perform consistent dip estimation for seismic imaging. Seismic imaging uses the recorded seismic data to reconstruct an image of the subsurface. Seismologists use ultrasensitive devices called geophones to record the sound waves as they echo within the earth. The customary, conceptual framework of imaging under the. Concepts and applications in 3d seismic imaging segeage disc. Seismic resolution the quality of seismic imaging over a fault zone is constrained by seismic resolution. Seismic imaging is a tool that bounces sound waves off underground rock structures to reveal possible crude oil and natural gasbearing formations. An overview of depth imaging in exploration geophysics john etgen1, samuel h. The key principles of seismic imaging are heuristically described in chapter 2, and. Moreover, the seismic data processing and fullazimuth 3d vsp have been enhanced by focusing on improved imaging and characterization of brazilian presalt reservoirs. An overview of depth imaging in exploration geophysics. This book introduces seismic imaging from the 3d perspective, starting from a 3d earth model.
Challenges in seismic imaging and reservoir characterization. It is a valuable resource for seismic processing practitioners and theoretical geophysicists. Seismic imaging by 3d partial cds method in complex media. Highresolution 2d seismic imaging in the noranda camp and. Us8463551b2 consistent dip estimation for seismic imaging. Walter lynn this course is designed for those working with reflection seismic data to understand and appreciate the underlying principles and processes leading to final images and associated attributes. Dvd includes a document in pdf format that has been specifically formatted. The goal of seismic imaging is to use these seismograms to reconstruct the earth model, such as the re. Focused gaussian beams provide an added level of controllability of the individual beam solutions. Several processing methodologies were used, including inhouse algorithmsworkflows in addition to service companies solutions. The images is made using a synthetic focusing technique which also needs a smooth velocity model of the earths crust for focusing the image. Recently, however, 3d seismic imaging techniques are used where a fully comprehensive prospect evaluation is desired or where mine planning issues need to be addressed eaton et al.
The seismic data were acquired at the university of calgary seismic physical modeling facility, which is maintained by the consortium for research in elastic wave exploration seismology crewes. Overviews are often useful and this paper is written for the geophysicist who has not been deeply involved with the design and analysis of 3d seismic survey acquisition for the past 15 years or so, and would like to have an idea of what happened, whats happening now and what is likely to. In the 1970ties and 80ties, many tests of highresolution seismic imaging methods for mineral exploration have had only limited success. Seismic images are crucial to todays exploration and reservoir monitoring. Concepts and applications in 3d seismic imaging by biondo biondi. The book coherently presents the main components of seismic imaging.
1416 990 181 36 1098 1535 843 1290 593 114 1360 410 1352 1356 757 1152 682 1179 1156 1656 1609 476 1142 628 941 366 1651 841 690 976 1487 981 809 1461 655 1006 236 580