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. In this thesis, i focus on two uncertainty sources that a ect seismic imaging. 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. An overview of depth imaging in exploration geophysics. Seismic imaging computational scale imaging integral formulation. Using vertical seismic profile vsp data to define where selected thinbed gas reservoirs were positioned in a 3d seismic data volume, we created horizon slices through this 3d image that showed the reflection amplitude behavior across the depositional surfaces where targeted thinbed reservoirs were located. Recently, however, 3 d 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. We are now ready to represent the seismic imaging operation in terms of matrixvector algebra. Km is still used in optimization schemes where cheap inexact iterations are useful. In fact, the first use of groundpenetrating radar was to determine a glaciers depth in 1929.
This book, 3 d seismic imaging, aimes at helping academic seismology to catchup with industrial practices by introducing the theory of seismic imaging from the 3 d perspective. In addition to providing excellent structural images, the dense sampling of a 3 d survey makes it possible to map reservoir quality and the distribution of oil and gas. Nov 21, 2012 for the love of physics walter lewin may 16, 2011 duration. In the past decade, 3d reflection seismology has almost entirely replaced 2d seismology in the seismic industry. Recording 3d surveys has become the norm, instead of the exception. This conventional approach to 3d survey design is limited by an incomplete understanding of the differing properties of the many geometries that can be used in 3d seismic surveys. Using vertical seismic profile vsp data to define where selected thinbed gas reservoirs were positioned in a 3 d seismic data volume, we created horizon slices through this 3 d image that showed the reflection amplitude behavior across the depositional surfaces where targeted thinbed reservoirs were located. Pdf the 3 d velocity structure of the deep mantle has been recently inferred from imaging procedures such as migration, tomography, stacking, and. This technology allows chevron scientists to see beneath the earths surface more clearly and accurately than ever before. Using seismic imaging to map formations below the seafloor. These gains are not only tallied through advances in casing, drill string or cutting technologies but also through the unsung technologies that have been recently employed and of them, 3d seismic imaging has seen the greatest returns on investment. Challenges in seismic imaging and reservoir characterization. In the past decade, 3 d reflection seismology has almost entirely replaced 2d seismology in the seismic industry. A mathematical view of re ection seismic imaging, as practiced in the petroleum industry.
In addition to providing information about subsurface formations, the indirect detection of dense contaminants including dense nonaqueous phase liquids dnapls may be possible from the seismic data. For the love of physics walter lewin may 16, 2011 duration. Seismic imaging technology seismic imaging is considered key to reduce risk and cost in exploratory as well as development drilling. Challenges in seismic imaging and reservoir characterization of presalt oilfields in offshore brazil. In seismic exploration, many decisions are based on interpretations of seismic images, which are a ected by multiple sources of uncertainty. N o 109 is the number of output image points n i 108 is the number of input data traces f 30 is the number of cyclespointtrace f n o n i 3 x 1018 cycles 30 cpuyears. Diffraction tomography and multisource holography applied to. Geo manager new ventures, encana corporation now at burlington resources. One of the most powerful geophysical technologies is 3d seismic. The conventional seismic 2d technique provides an erroneous image of the subsurface, if the subsurface varies perpendicularly to the 2d seismic recording. However, academic research and teaching have struggled to keep up with the 3d revolution. Advanced seismic imaging techniques characterize the alpine fault. Due to the complicated field layout, timeconsuming preprocessing was necessary to create. Jones1 and ian davison2 abstract seismic imaging of evaporite bodies is notoriously difficult due to the complex shapes of steeply dipping flanks, adjacent overburden strata, and the usually strong acoustic impedance and velocity contrasts at the sedimentevaporite interface.
On the other hand, time migration schemes show low sensitivity to migration velocity errors and can be used as an intermediate step in seismic data processing for imaging seismic data. Matarese earth resources laboratory department of earth, atmospheric, and planetary sciences massachusetts institute oftechnology cambridge, ma 029 abstract fast algorithms exist for performing traveltime modeling, even in three dimensions. N o 109 is the number of output image points n i 108 is the number of input data traces f 30 is the number of cyclespointtrace f n o n i. An overview of depth imaging in exploration geophysics john etgen1, samuel h.
Recording 3 d surveys has become the norm, instead of the exception. Four decades ago, exxonmobil pioneered an exploration technology called 3d seismic, which uses sound waves to form sharp threedimensional images of underground formations, facilitating the. Show the formula for kirchho migration directly from the imaging condition 4. Chevrons proprietary seismic imaging technology helped the company achieve an exploration discovery rate of 66 percent in 2014.
In the third part, i present a method to improve the image resolution by mitigating attenuation. Thus, image uncertainty quanti cation is an important, albeit challenging task. Preprocessing of the seismic data included manual traveltime picking and assignment. Two dimensional geophysical imaging techniques have recently allowed for 2d imaging of mountain permafrost.
From industry selective targeting to academic systematic research part ii michael enachescu, ph d, p. Concepts and applications in 3d seismic imaging geoscienceworld. The process of imaging through modeling the velocity structure is a form of inversion of seismic data, and the term inversion is often used to imply building a velocity model which is iteratively improved until it and the seismic data are optimally in agreement. Geophysical companies profile the sea floor and use sound to create images thousands of feet below the subsurface. Seismic design specification for buildings, structures, equipment, and systems. In particular, the sampling requirements for optimal prestack imaging were not properly taken into account. Pdf seismic imaging methods are currently used to produce images of the earths subsurface.
Threecomponent and threedimensional seismic imaging by shaowu wang a thesis submitted to the faculty of graduate studies in partial fulfilment of the requirements for the degree of master of science department of geology and geophysics calgary, alberta august, 1997 c shaowu wang 1997. Fault correlation, horizon tracking, horizon flattening, and some image processing techniques can be adapted to the interactive environment to help improve interpretation. In this paper we study two approaches to seismic imaging. How 3d seismic imaging revolutionized the drilling industry. The application of 2d seismology is mostly limited to. Our general interest is imaging with underside reflections. The oilfield industry over the past several years has been making vast leaps in drilling efficiency. Pdf 3 d seismic interpretation download full pdf book. In addition to providing excellent structural images, the dense sampling of a 3d survey makes it possible to map reservoir quality and the distribution of oil and gas. Tradi tional holography, which uses a single source, is a method to reconstruct wavefronts from the phase and amplitude infor mation of the scattered wave field.
Seismic design specification for buildings, structures. The interactive environment with powerful 3 d visualization tools provides an efficient means for interpretation of the sheer volume of 3 d migrated seismic data. Introduction to seismic imaging alison malcolm department of earth, atmospheric and planetary sciences mit august 20, 2010. Standard migration techniques typically take into account only the first term of these respective series, which is the single scattering assumption ubiquitous in seismic imaging. Cggs seismic imaging experts emphasize 4d timelapse signal through optimizing seismic processing for 4d differences and minimizing 4d noise, providing clear monitoring of productionrelated reservoir changes. Between segments 2 and 3, and also between segments 3 and 4, overlapping geophones were used to align the records. Seismic imaging using crosswell surveys is another means of providing subsurface characterization and monitoring information. Introduction threedimensional 3 d seismic exploration is capable of providing the most complete subsurface picture of any surfacebased geophysical technique. The free gas zone beneath gas hydrate bearing sediments and its link to fluid flow.
Concepts and applications in 3d seismic imaging seg distinguished instructor series no. Husky energy senior fellow in exploration geophysics associate professor and consultant, memorial university john hogg. We assess the feasibility of highresolution seismic depth imaging in deep water based on a. Concepts and applications in 3d seismic imaging by biondo biondi.
Pdf the 3d velocity structure of the deep mantle has been recently inferred from imaging procedures such as migration, tomography, stacking, and. Biondi and others published 3 d seismic imaging find, read and cite all the research you need on researchgate. Biondi and others published 3d seismic imaging find, read and cite all the research you need on researchgate. Threecomponent and threedimensional seismic imaging. Introduction to marine seismic technologies a challenge under the sea because nearly a third of all oil produced today comes from offshore wells and most of the worlds untapped oil reserves are in deepwater environments, the future of energy is intimately tied to seismic data. Seismic modeling studies based on field analogues represent an important tool to close the scale gap between observations from outcrops and seismic data and to support seismic interpretation. Imaging the subsurface with 2d and 3d seismic data. In seplib3d, to describe the irregular data geometry, we associate each seismic trace with a trace header, as. Imaging techniques in seismic geomorphology jim bock1 and vladimir rybakov2. The interactive environment with powerful 3d visualization tools provides an efficient means for interpretation of the sheer volume of 3d migrated seismic data. However, academic research and teaching have struggled to keep up with the 3 d revolution. The reconstructed wave front can give a threedimensional3d image.
By developing the theory of seismic imaging from basic principles, the authors relate the different models of seismic propagation, reflection and imaging thus providing links to reflectivitybased imaging on the one hand and to nonlinear seismic inversion on the other. Gray2, and yu zhang3 abstract prestack depth migration is the most glamorous step of seismic processing because it transforms mere data into an. Multicomponent processing and transforms monday afternoon, october 24th offline imaging using 3component seismic data ye zheng and robert r. In the 1970ties and 80ties, many tests of highresolution seismic imaging methods for mineral exploration have had only limited success. Distributed computing of seismic imaging algorithms arxiv. Jan 10, 2015 four decades ago, exxonmobil pioneered an exploration technology called 3 d seismic, which uses sound waves to form sharp threedimensional images of underground formations, facilitating the. Seismic imaging of continents and their margins research school.