Full waveform inversion and velocity analysis workshop ii. Full waveform inversion fwi is nonlinear datafitting procedure that aims at obtaining detailed estimates of subsurface properties from seismic data, which can be the result of either passive or active seismic experiments. Full waveform inversion fwi delivers highresolution images of the subsurface by minimizing iteratively the mis t between the recorded and calculated seismic data. We use in silico simulations to demonstrate that fullwaveform inversion, a computational technique originally developed in geophysics, is able to generate accurate threedimensional images of the. Full waveform inversion fwi with waveequation migration. Guided wave tomography based on full waveform inversion. W024 full waveform inversion for reflected seismic data. We use in silico simulations to demonstrate that full waveform inversion, a computational technique originally developed in geophysics, is able to generate accurate threedimensional images of the. The inversion is formulated as a nonlinear least squares problem which minimizes errors between synthetic and observed data.
Land and shallow water wei zhang and nanxun dai, cnpcbgp. Fullwaveform inversion on heterogeneous hpc systems. All of the abovementioned practical applications of controlledsource fullwaveform inversion ignore the free surface, embed shots and receivers in the model, and remove surfacerelated phases from the data as much as possible. Full waveform inversion fwi is a data matching procedure which attempts to use the whole wavefield to obtain quantitative information about the subsurface. Full waveform inversion for seismic velocity and anelastic. Full waveform inversion for borehole seismic data is an illposed problem and constraining the problem is crucial. Fullwaveform inversion fwi is a challenging datafitting. Effects of surface scattering in fullwaveform inversion. Function and technical implementation of the full waveform inversion, use of the complete seismic amplitude and phase information, sample data and evaluation of the ettlinger line. Lecture notes on full waveform inversion seiscope consortium.
Gary margrave and rob ferguson and chad hogan subject. The widespread strategy of seismic imaging, the single scattering formulation, at the core of fwi, as. Full waveform inversion strategy for density in the frequency. The challenge presented by saudi aramco is to solve. Full waveform inversion fwi is a machine learning algorithm with the goal to find. Seiscl can be run either on gpus with cuda or opencl, or cpus. All of the abovementioned practical applications of controlledsource full waveform inversion ignore the free surface, embed shots and receivers in the model, and remove surfacerelated phases from the data as much as possible. An introduction to full waveform inversion isterre. Full waveform inversion fwi constructs the medium parameters tarantola, 1984 by minimizing the misfit between the observed and simulated data. I present an overview of fullwaveform inversion fwi, focusing on its use in seismic exploration. Fullwaveform inversion seismic laboratory for imaging.
Full seismic waveform modelling and inversion top results of your surfing full seismic waveform modelling and inversion 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. It has been attacked successfully with the gaussnewton method and sparsity promoting regularization based on. Full waveform inversion fwi with an imageguided gradient improves convergence by reducing the number of parameters in the subsurface model. Full waveform inversion fwi is a challenging datafitting procedure based on full wavefield modeling to extract quantitative information from seismograms.
In this work, we try to present a computational tractable method based on the bayesian framework to analyze different statistical parameters of the fwi result. Towards full waveform ambient noise inversion geophysical. Fullwaveform inversion for borehole seismic data is an illposed problem and constraining the problem is crucial. In this paper, a guided wave tomography method based on full waveform inversion fwi is developed for accurate and highresolution reconstruction of the remaining wall thickness in isotropic plates. Ultrasound imaging is portable and universally safe, but existing modalities cannot image usefully inside the adult human skull. If the exact physical properties of the subsurface are known, it should be possible to generate synthetic data which exactly match the measurements made in a seismic survey, provided that. Recent advances in full waveform inversion youtube.
While there is an extensive and growing literature on the topic, publications focus mostly on technical aspects, making this topic. Full waveform inversion in an anisotropic world eage. Pdf full waveform inversion with extrapolated low frequency. To see the motivation for and the high expectations in full waveform inversion, we brie. The fullwaveform modeling is implemented in frequency domain using the finite. An overview of fullwaveform inversion in exploration geophysics. Pdf fullwaveform inversion fwi is a challenging datafitting procedure based on. In this study we solve a psv wave system along a 2d vertical cross section of isotropic wave velocities and density. Modeling is performed with finitedifference in the timedomain, and can be either 3d or 2d, isotropic acoustic, elastic or viscoelastic. This site is like a library, use search box in the widget to get ebook that you want. Full waveform inversion full waveform inversion fwi derives highresolution velocity models by minimizing the difference between observed and modeled seismic waveforms.
Although many implementations are only acoustic hence not really full, for the purposes of neatness we will follow virieux and operto 2009 and use full waveform inversion fwi in this article. Full waveform inversion fullwaveform inversion fwi derives highresolution velocity models by minimizing the difference between observed and modeled seismic waveforms. A method of determining seismic data velocity models comprising dipguided full waveform inversion that obtains a better velocity model with less computational requirements. Sparsepromoting full waveform inversion based on online. To avoid this problem, waveform inversion has been performed under the assumption that poissons ratio and density are fixed over the entire model brossier et al. An overview of fullwaveform inversion in exploration geophysics j. Full waveform inversion for seismic velocity and anelastic losses in heterogeneous structures by aysegul askan, volkan akcelik, jacobo bielak, and omar ghattas abstract wepresentaleastsquaresoptimization methodforsolvingthenonlinear full waveform inverse problem of determining the crustal velocity and intrinsic at. The availability of lowfrequency data is an important factor in the success of fullwaveform inversion fwi in the acoustic regime. Constraints can be imposed on the data and model space through covariance matrices. The low frequencies help determine the kinematically relevant, lowwavenumber components of the velocity model, which are in turn needed to avoid convergence of fwi to spurious local minima.
Pdf full waveform inversion with imageguided gradient. The presented joint inversion example demonstrates that full waveform ambient noise inversion has the potential to improve the resolution of tomographic images compared to traditional ambient noise tomography and, in addition, to refine noise source location. Fullwaveform inversion imaging of the human brain npj. Dgfwi quickly converges to provide a better image, obtains better amplitudes, and relies less on lower frequencies. Pratt, 1999 to obtain a dimension reduction technique e.
Since its reintroduction by pratt 1999, fullwaveform inversion fwi has gained a lot of attention in geophysical exploration because of its ability to build high resolution velocity models more or less automatically in areas of complex geology. Oct 14, 2015 full waveform inversion fwi is now a widely established theory of geophysical imaging, yet not fully applied in practise due to limitations of seismic acquisitions, seismic simulations. For the data space, signal polarization information can be used to evaluate the data uncertainties. Full waveform inversion with extrapolated low frequencies. Full waveform inversion and velocity analysis part of the long program computational issues in oil field applications. An improvement of the latter is essential for a better understanding of noise generation. Herrmann1 1the university of british columbia, department of earth, ocean and atmospheric sciences. The processing and interpretation of seismic survey data has undergone a number of revolutions since industrial seismology began in the 1920. The forward model is computed in the frequency domain by solving a fullwave. Dec 17, 2014 elegant tea jazz relaxing intrumental jazz music for work,study,reading relax music 6,481 watching live now.
Here we use the opportunity provided by recent dense deployments of broadband stations in the region to obtain a new model of the western mediterranean crust and mantle, using fullwaveform inversion of threecomponent recordings in the period range 12120 s. Full language confusion 4 part i numerical solution of the elastic wave equation. Full seismic waveform modelling and inversion advances in. Elastic fullwaveform inversion fwi is a new borehole seismic application that provides direct estimates of elastic rock parameterscompressional and shearwave velocities v p and v, respectively, density, and thomsens epsilon and deltafrom minimally processed 3d vsp and walkaway vsp recordings. However, acquiring data below 2 or 3 hz from the field is a challenging. Workshop on geophysical data analysis and assimilation. However, in the field of full waveform inversion, research associated to the uncertainty quantification is rare due to the huge computational cost of solving wave equations. Crewes research report volume 22 2010 created date. An overview of fullwaveform inversion in exploration. To relax the dependence on low frequency reflections, we revisit full waveform inversion. Operto2 abstract full waveform inversion fwi is a challenging data. Fullwaveform inversion with extrapolated lowfrequency data. Pdf introduction to seismic full waveform inversion as part of the lecture. Fullwaveform inversion of gpr data for civil engineering.
Magnetic resonance imaging and xray computed tomography provide the two principal methods available for imaging the brain at high spatial resolution, but these methods are not easily portable and cannot be applied safely to all patients. Full 3d seismic waveform inversion download ebook pdf, epub. Semidiscrete matrixfree formulation of 3d elastic full. For this reason, elastic full waveform inversion is more likely to become trapped in local minimum. Full waveform tomography is a tomographic technique that takes advantage of numerical solutions of the elastic wave equation. Full waveform inversion fwi is a powerful tool to reconstruct subsurface geophysical parameters with high resolution. Full waveform inversion fwi with waveequation migration wem and well controlwem and well control garyyg margrave rob ferguson chad hogan banff, 3 dec. Seismic full waveform inversion fwi is a stateoftheart technique for estimating subsurface physical models from recorded seismic waveform, but. Seismic full waveform inversion fwi is a stateoftheart technique for estimating subsurface physical models from recorded seismic waveform, but its application requires care because of high.
Crust and upper mantle of the western mediterranean. Full waveform inversion fwi is an emerging subsurface. The fullwaveform inversion fwi for a large number of unknowns uses gradientbased optimization methods where a 3d to 2d conversion is used to apply this method to experimental data. I consider the typical data acquisition scenarios used by industry, and discuss the progression of velocity model building and imaging techniques that have been employed to extract increasing amounts of information from seismic data. Highresolution imaging at half the propagated wavelength is expected. Full waveform inversion fwi with waveequation migration wem and well control author. Outline the fwi cyclethe fwi cycle the fundamental theorem of fwi. In this we address the optimal parallelisation configurations of individual simulations, the large io requirements of adjoint simulations, and the scheduling of large numbers of forward and adjoint solves, typical for realistic inversions. Well, a simple visual characterization depicting the difference between what the two approaches bring to the table can be realized using the common street artist pencil and brush. Fullwaveform inversion of gpr data in frequencydomain. The accuracy of the numerical solutions and the exploitation of complete waveform information result in tomographic images that are both more realistic and better resolved.
Improved image quality allows detailed seismic analyses, accurate identification. This is achieved iteratively by determining and minimizing a residual. Fullintensity waveform inversion yike liu 1, bin he, huiyi lu, zhendong zhang2, xiaobi xie3, and yingcai zheng4 abstract many fullwaveform inversion schemes are based on the iterative perturbation theory to fit the observed waveforms. Crosstalkfree simultaneoussource full waveform inversion. A new fullwaveform inversion scheme is developed to obtain highresolution images of crosshole ground penetrating radar gpr data. As 3d surveys become widely implemented, corresponding 3d processing techniques are required to solve complex geological cases, while a large amount of computation is the most challenging problem. Fullwaveform inversion seismic laboratory for imaging and. In seismic wave inversion, seismic waves are sent into the ground and then observed at many receiving points with the aim of producing highresolution images of the geological underground details. Its high resolution has attracted a great attention mora, 1987, plessix, 2006, guitton and diaz, 2012, operto et al. Click download or read online button to get full 3d seismic waveform inversion book now. Sparsepromoting full waveform inversion based on online orthonormal dictionary learning lingchen zhu, entao liu, and james h. Elastic full waveform inversion with sourceindependent. The inversion forces the synthetic data to fit the.
Full seismic waveform modelling and inversion by andreas fichtner contents 1 preliminaries 1 1. Seiscl is a program to perform seismic modeling, full waveform inversion and reverse time migration. Full seismic waveform modelling and inversion springerlink. It goes beyond refraction and reflection tomography techniques, which use only the travel time kinematics of the seismic data, by using additional information provided by the. Highfrequency acoustic land fullwaveform inversion. We present a spectralelement implementation of full seismic waveform inversion for large heterogeneous hpc systems. When the observed waveforms lack low frequencies, those schemes may encounter convergence problems due to.
Pdf an overview of fullwaveform inversion in exploration. The present disclosure generally relates to dipguided full waveform inversion dgfwi that combines dipguide methodology hale, 2009 with the full waveform inversion fwi process e. The development of full waveform inversion techniques has always been considered a crucial step towards a more detailed understanding of subsurface properties. Pdf lectures on full waveform inversion overview researchgate. Software for viscoelastic full waveform inversion on large. Full3d seismic waveform inversion theory, software and. Full waveform inversion strategy for density in the. The wave equation is solved by using a fourthorder variant. Mcclellan center for energy and geo processing cegp at georgia tech and kfupm 75 fifth street nw, atlanta, ga 30308 november 7, 2016 abstract full waveform inversion fwi delivers highresolution images of the.
Conditioning full waveform inversion to welcome anisotropy. Full waveform inversion using preserved amplitude reverse time migration fwi 5. Offground gpr data, measured over homogeneous concrete specimens, were inverted using the fullwaveform inversion. Applications of fullwaveform inversion fwi to land seis mic data exhibit. Fullwaveform inversion fwi is a challenging datafitting procedure based on full wavefield modeling to extract quantitative information from seismograms. Full 3d seismic waveform inversion download ebook pdf. To achieve this, it requires refracted waves or low frequencies in the reflectionrefraction data. Aud 4 no full waveform inversion based on scattering angle enrichment with application to real data set fwi 5. Fullwaveform inversion imaging of the human brain biorxiv. Request pdf elastic full waveform inversion with sourceindependent crosstalk free sourceencoding algorithm elastic full waveform inversion fwi is more suitable to process multicomponent. Pdf full wave form inversion for seismic data ibrahim.
Guided wave tomography based on full waveform inversion abstract. Full waveform inversion fwi is a high resolution seismic imaging technique that is. Modern inversion methodologies in seismology date back to the pioneering work of backus and gilbert 1967, 1970 on the determination of global structure from free oscillations of the earth. We propose an adaptive variablegrid 3d fwi on graphics processing unit devices. Operto2 abstract fullwaveform inversion fwi is a challenging data. We represent the subsurface model with a sparse set of values, and from these values, we use imageguided interpolation igi to compute finelyand uniformlysampled gradients of the data misfit function in fwi. While imaging provides us with what we could describe as a pencil sketch of. Totalvariation regularization strategies in fullwaveform. Full waveform inversion fwi is a methodology that seeks to find highresolution, highfidelity velocity models of the subsurface capable of matching individual synthetic seismic waveforms with an original raw field dataset. Full waveform inversion has been successful in building high resolution velocity models for shallow layers. The availability of low frequency data is an important factor in the success of full waveform inversion fwi in the acoustic regime. Given an initial guess of the subsurface parameters, a model the data are predicted by solving a waveequation.
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