Professor schuster s research interests are in seismic imaging, interferometry, waveform inversion, em methods, seismic field techniques, and the use of novel methods for super resolution imaging. The basic principle of such methods is to randomly draw a batch of realizations of a given misfit function and goes back to the 1950s. Velocity model building from seismic reflection data by. The viability of these simulations is predicated on the availability of earth models of suf. Quality control and preconditioning of the input data. In exploration geophysics, seismic imaging has been in use for over 20 yr, where inversion proceeds mainly from traveltime baig et al. To further simplify the inversion, we assume that the wavelet is known. Seismic inversion algorithms span the range between two extremes. Ebook introduction to seismic inversion methods as pdf. Interferometricdaylight seismic imaging schuster 2004. Seismic inversion the best tool for reservoir characterization. Seismic inversion, or tomography, is the procedure for reconstructing earth properties from seismic data. Mapping full seismic waveforms to vertical velocity pro les.
Seismic waveform inversion by stochastic optimization tristan van leeuwen, aleksandr aravkin and felix j. Seismic inversion describes the theory and practice of inverting seismic data for the subsurface rock properties. Crains petrophysical handbook seismic inversion basics. Schuster, describes the theory and practice of inverting seismic data for the subsurface rock properties of the earth. The ultimate goal of such an approach is to dramatically reduce the computational cost involved in evaluating the misfit. Cnns are trained to map the seismic data directly into velocity logs. Acoustic waveequation traveltime and waveform inversion of. Schuster, and sia hassanzadeh abstract a hybrid waveequation traveltime and waveform inversion method is presented that reconstructs the interwell velocity distribution from crosshole seismic data. Wellto seismic match, zerophasing of data in zone of interest and extraction of the wavelet.
Full waveform inversion for seismic velocity and anelastic. Schuster department of earth science and engineering, king abdullah university of science and technology, thuwal, saudi arabia, 239556900. Inversion was used to improve the prediction of reservoir properties from the 3d seismic. In other words, if we had drilled and logged wells at the cmps, what. The input to the autoencoder is the recorded common shot gathers, and the implicit function theorem is used to determine the.
The background image on the far right is an actual seismic section. The primary application is for inverting reflection andor transmission data. Our smooth inversion tomographic method is based on physically realistic modeling of first break propagation for pwave and swave surveys. Seismic inversion by newtonian machine learning abstract. To combine the multiscale fwi and phase inversion methods, sun and schuster. Algorithm and methodology for application to the salt structure inversion g. In a seismic inversion the original reflectivity data, as typically recorded routinely, is converted from an interface property i.
There are also numerous other impedance methods used in avo, such as the elastic impedance ei and extended. This allows us to integrate well data into the inversion and to simplify the mapping by using the regularity of active seismic acquisition. Witte, mathias louboutin, fabio luporini, gerard j. It relates the different models of seismic propagation, reflection, and imaging providing links to reflectivitybased imaging and to nonlinear seismic inversion. The input to the autoencoder is the recorded common shot gathers, and the implicit function theorem is. Again, notice the excellent delineation of the gas sand. Apr 24, 2019 we present a waveequation inversion method that inverts skeletonized data for the subsurface velocity model. Inversion includes both seismic field data and well data, where well data serves to add the high frequency below the seismic band and to constrain the inversion. Schuster 1991a suggested a skeletonized inversion method which.
Well logs are first conditioned and edited to ensure there is a suitable relationship between impedance logs and the desired properties. An introduction to full waveform inversion isterre. This inversion procedure leads us to a seismic volume that portrays layer properties in terms of impedance rather than interface characteristics, and assumes that the reflecting horizons have already been properly migrated to their appropriate positions. Introduction to seismic inversion methods top results of your surfing introduction to seismic inversion methods start download portable document format pdf and ebooks electronic books free online rating news 20162017 is books that can provide inspiration, insight, knowledge to the reader. In stochastic inversion, the vertical variogram model controls the high frequencies. Mapping full seismic waveforms to vertical velocity pro. Other views of the earth using seismic data are shown in figure 1. Because seismic wavelets are bandlimited and seismic data are finite and inaccurate, there exist an infinite number of reflectivity series that can fit the data equally well. The primary application is for inverting reflection. Well logs are first conditioned and edited to ensure there is a suitable relationship. For both deterministic and stochastic inversion, the seismic amplitudes control intermediate frequencies within the seismic bandwidth. Chen1 1school of earth sciences, zhejiang university, hangzhou, china, 2modeling and imaging laboratory, earth and planetary sciences, university of california, santa cruz, ca, usa.
Seismic inversion investigations in geophysics seg library. Seismic inversion aims to reconstruct a quantitative model of the earth subsurface, by solving an inverse problem based on seismic measurements. When iterated, this method corresponds to iteratively reweighted least squares with a simulated l 1 norm for vector p trad etal. The presented approach uses gathers of neighboring common midpoints cmps for the estimation of a vertical velocity log. Pdf seismic inversion methods and some of their constraints.
Introduction to seismic inversion seismic inversion. The objective of seismic inversion is to convert reflectivity data interface properties to layer properties. In the second poststack inversion paper, singh proposes a technique for performing poststack seismic inversion in the depth domain. Schuster seismic inversion describes the theory and practice of inverting seismic data for the subsurface rock proper ties of the earth. To determine elastic parameters, the reflectivity from avo effects must be inverted. Seismic inversion is a technique that has been in use by geophysicists for almost forty years. This book describes the theory and practice of inverting seismic data for the subsurface rock properties. Preface this book describes the theory and practice of inverting seismic data for the subsurface rock properties of the earth.
There are several ways to achieve this objective, as will be shown later on. Since full waveform modelling is signi cantly nonlinear with respect to velocities, monte carlo. A newtoncg method for largescale threedimensional elastic. This inversion, called seismic inversion for reservoir characterization, reads between the lines, or between reflecting interfaces, to produce detailed models of rock properties. Note that in the strict sense, the inversion described for migration or imaging. Acoustic waveequation traveltime and waveform inversion of crosshole seismic data changxi zhou, wenying cai, yi gerard t.
Seismic waveform inversion by stochastic optimization. Inversion transforms seismic reflection data into rock and fluid properties. This book describes the theory and practice of inverting seismic data for the subsurface rock properties of the earth. Used to image and analyze reservoir changes in pressure and fluid saturation to optimize hydrocarbon recovery. The principle objective of seismic inversion is to transform seismic reflection data into a quantitative rock property, descriptive of the reservoir.
Data considerations for inversion prestack andor poststack time migrated seismic data well data conditioning and editing is necessary wavelet estimation required for all modern inversion approachesdeterministicstatistical low frequency trend absolute acoustic impedance contains a low frequency trend that must be obtained usually from well control or. Anyone using inversion algorithms, or interpreting resultant images, must be familiar with the basic principles. Seismic inversion methods and some of their constraints. For simplicity, the following discussion describes only modelbased inversion. Welltoseismic match, zerophasing of data in zone of interest and extraction of the wavelet. The wide spread strategy of seismic imaging, the single. Inversion in itself means to undo an operation,but here it represents the transformation of a seismic amplitude cube into an acoustic or elastic impedance cube. Velocity model building from seismic reflection data by full. Seismic inversion is a somewhat confusing expression. Stochastic vs deterministic pre stack inversion methods. Basics of seismic imaging king abdullah university of. According to bayes theorem, pmjd obs pd obsjmpm pd obs 1 where pd. Some other alternatives are spaceadaptive and discrete spike inversions. As we will show in our data examples, this reduction in resolution is modest and often quite tolerable for multiscale phase inversion.
Thickness and porosity are fairly easy to predict, and some distinction may be made between gassaturated reservoir and wet reservoir. Developments, workflow, and case studies huyen bui, arthur weglein, sunil kumar, scott singleton, oswaldo davogustto cataldo, malleswar yenugu, samarjit chakraborty, and ramses meza. In its most simple form, acoustic impedance logs are computed at each cmp. Tulsa, ok, 12 july 2017 seismic inversion, by gerard t. Pdf seismic inversion by newtonian machine learning. April 25, 2019 seismic inversion by newtonian machine learning running head. Society of exploration geophysicists releases seismic inversion by gerard t. Bayesian methods update a prior probability density function pdf pm with new information from the data to produce a probability distribution of model parameters post inversion, which is often called a posterior pdf, written as pmjd obs. A profitable development of an oil or gas field starts with a good understanding of the subsurface as a basis for efficient and successful field management. Seismic inversion conventional seismic impedance inversion and advanced seismic inversion techniques. Full waveform inversion fwi is a high resolution seismic.
Fullwaveform inversion of shortoffset, bandlimited seismic data in. Cgg geoconsulting has developed a 4d inversion workflow extending the 3d simultaneous elastic inversion to joint multivintage inversion, with simultaneous inversion of all angle stacks for base and monitor surveys. These predictions should become more accurate as wells are added. Fullwaveform inversion of shortoffset, bandlimited seismic data in the alboran. There are at least three fundamental issues to be solved simultaneously.
We explore the use of stochastic optimization methods for seismic waveform inversion. The skeletonized representation of the seismic traces consists of the lowrank latentspace variables predicted by a welltrained autoencoder neural network. Schuster, waveequation traveltime inversion, geophysics 56. Seismic inversion is essentially a very simple procedure. Seismic inversion and synthetic sonic logs calibration of seismic attributes to ground truth is still an emerging science. As examples, we show that ii can image reflectivity distributions by migrating ghost reflections in passive seismic data and generalizes the receiver.
It is a valuable resource for seismic processing practitioners and theoretical geophysicists. The primary application is for inverting reflection andor transmission data from engineering or exploration surveys, but the methods described also can be used for earthquake studies. Early inversion techniques transformed the seismic data into pimpedance the product of density and pwave velocity, from which we were able to make predictions about lithology and porosity. Interferometric seismic imaging is defined to be any algorithm that inverts correlated seismic data for the reflectivity or source distribution. There is a bright future for the use of geophysics but it requires that inversion be applied with care and understanding. Corner seismic inversion successfully predicts interpreters. We apply coherency enhancement to a timemigrated seismic image from a gulf of mexico dataset claerbout,2005,showninfigure1. His geophysical lab is equipped with stateoftheart seismographs for 624 channel recording and a 72channel resistivity array for both exploration. Seismic inversion geoscienceworld books geoscienceworld.
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