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Keywords: hessian
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Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, October 11–16, 2020
Paper Number: SEG-2020-3426967
... present multi-iteration image-domain least-squares migration (LSM) by approximating the Hessian through point spread functions (PSFs). Since information in a migration image is insufficient to uniquely determine a reasonable reflectivity model and LSM itself can cause artifacts, we include an L p -norm...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, October 11–16, 2020
Paper Number: SEG-2020-3419762
... reflection hessian cmp gather exploration geophysicist 10 velocity analysis primary reflection We propose a deep neural network (DNN) framework for computing hyperbolic Radon transform for separating primary reflections and multiples. The basic idea is to compute the weights associated with the...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, October 11–16, 2020
Paper Number: SEG-2020-3427176
... low to intermediate wavenumber components of the subsurface model. Nevertheless, the RWI is a highly nonlinear problem requiring careful preconditioning to avoid the local minima and accelerate the convergence rate. The Hessian operator is the second-order derivative of the objective function...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, October 11–16, 2020
Paper Number: SEG-2020-3428147
...-scatter model, which alone takes twice the computation of RTM. And to avoid interference, the impulse scatters cannot be sampled densely enough. In this paper, we deduced an analytic expression of Hessian/PSF under the WKJB-approximation. And with it we are able to explicitly calculate the PSFs at any...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3215177
.... We propose a single-iteration LS-RTM, where the approximate Hessian operator is estimated as a matching filter. Based on the consideration that subsurface reflectivity is sparse, the estimated filter is given as input to a sparse inversion. The proposed method is then illustrated through synthetic...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3216560
... approximate Hessian information to construct a proposal distribution, which is a local Gaussian distribution. New samples/models can be easily drawn from the proposal distribution. The new samples/models are then subjected to the accept/reject Metropolis-Hasting (M-H) criterion. The solutions to FWI are then...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3216779
... ray path criterion traveltime ray seg international exposition anisotropic media equation derivative eigenray method annual meeting phase shift stationary path reservoir characterization variation arc length formulation upstream oil & gas gradient hessian cervený...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3216695
... that requires both gradient and Hessian of the traveltime with respect to nodal locations and ray velocity directions. In this work we show how the global Hessian matrix of the stationary ray can be used to compute and geometric spreading. We compare the accuracy of geometric spreading computed by our...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3215537
... ABSTRACT In this paper, we show a comparison of three uncertainty estimation methods in the context of non-linear seismic inversion with a convolutional forward model. The first method is based on a deterministic inversion where the uncertainty is extracted from the Hessian matrix of the...
Proceedings Papers

Paper presented at the SEG International Exposition and Annual Meeting, September 15–20, 2019
Paper Number: SEG-2019-3216008
... ABSTRACT Full waveform inversion enables us to obtain high-resolution subsurface images. However, estimating the associated uncertainties is not trivial. Hessian-based method gives us an opportunity to assess the uncertainties around a given estimate based on the inverse of the Hessian...
Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2998434
... We propose using two non-stationary operators to represent the amplitude and frequency variations in the least-squares Hessian to account for the principal differences between conventional and least-squares migrated images. The calculation and application of these operators are computationally...
Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2997617
... structures. Hence, we want to use this information in FWI with exact Hessian matrix, for they carry more information about second-scattering waves compared with first-order directions. A few studies have demonstrated the possibility of applying the approximate Hessian and exact Hessian to FWI. In this study...
Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2997924
... ABSTRACT Accounting for the Hessian in full waveform inversion can lead to higher convergence rates, improved resolution, and better mitigation of parameter trade-offs in the multi-parameter case. In spite of these potential advantages, the widespread adoption of second-order optimization...
Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2998233
... ABSTRACT We propose a method for constructing the Hessian in Elastic Full Waveform Inversion (EFWI) as a series of Hessian-vector products with model perturbations. The assembled Hessian of both simple and complex synthetic models are studied to draw conclusions regarding spatial resolution...
Proceedings Papers

Paper presented at the 2018 SEG International Exposition and Annual Meeting, October 14–19, 2018
Paper Number: SEG-2018-2997009
... model element data simplification hessian artifact mapping migration inversion annual meeting reservoir characterization seg international exposition linearized inversion modeling operator lsmig upstream oil & gas kirchhoff migration model space noise operator...
Proceedings Papers

Paper presented at the 2017 SEG International Exposition and Annual Meeting, September 24–29, 2017
Paper Number: SEG-2017-17588650
... annual meeting crosstalk artificial intelligence waveform inversion full waveform inversion frequency band seg seg international exposition iteration reservoir characterization innanen hessian information upstream oil & gas qfwi inversion optimization geophysics...
Proceedings Papers

Paper presented at the 2016 SEG International Exposition and Annual Meeting, October 16–21, 2016
Paper Number: SEG-2016-13879108
... the Hessian of the cost function, both of which are computationally expensive. In this work, we propose a new method to quantify uncertainties based on a novel formulation of the full-waveform inversion problem – wavefield reconstruction inversion. Based on this formulation, we formulate a...
Proceedings Papers

Paper presented at the 2016 SEG International Exposition and Annual Meeting, October 16–21, 2016
Paper Number: SEG-2016-13871529
... parameterizations are studied: stiffnesses versus velocity and Thomsen’s parameters. The inversion results are analyzed for sensitivity and crosstalk. I also investigate the use of the Hessian to precondition the objective function’s gradient and to reduce crosstalk between different parameters. The synthetic...
Proceedings Papers

Paper presented at the 2016 SEG International Exposition and Annual Meeting, October 16–21, 2016
Paper Number: SEG-2016-13879808
... crosstalk between parameters. We show a second order method is promising in time-lapse FWI by applying the approximated inverse of the Hessian to the gradient. Presentation Date: Monday, October 17, 2016 Start Time: 4:35:00 PM Location: Lobby D/C Presentation Type: POSTER fwi hessian inversion...
Proceedings Papers

Paper presented at the 2016 SEG International Exposition and Annual Meeting, October 16–21, 2016
Paper Number: SEG-2016-13944663
... . Tang , Y. , 2009 , Target-oriented wave-equation least-squares migration with phase encoded hessian : Geophysics , 74 , no. 6 , WCA95 – WCA107 , 10.1190/1.3204768 . Zhang , Y. , and J. Sun , 2009 , Practical issues in reverse time migration: True amplitude...

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