... Developing fast and scalable solvers for frequency-domain wave propagation is a notoriously difficult problem in mathematics and scientific computing. One challenge is that classical discretization techniques such as finite difference methods yield indefinite discrete systems that preclude use...

... We develop a 3D eikonal solver based on the fast sweeping method to numerically simulate bed-boundary effects on azimuthal borehole acoustic measurements acquired in highangle or horizontal (HA/HZ) wells. A fast and effective solver is essential for real-time and reliable interpretation in HA/HZ...

... with a direct solver. The method calculates derivatives directly from the linear system generated by the finite element code at the cost of additional substitution phases for the same matrix factorization performed for the forward problem in the inversion iteration. A validation example is presented...

... characterization computer based training neural network machine learning upstream oil & gas artificial intelligence dataset international gpus exploration geophysicist fwi solver society full waveform inversion american association equation node deep learning deep-learning software accelerator...

... siahkoohi interface algorithm imaging inversion operator solver upstream oil & gas artificial intelligence herrmann international software geophysics application quantification devito american association applied geoscience exploration geophysicist Accelerating innovation...

... upstream oil & gas local solver local domain implementation reservoir characterization simulation reflection elastic local solver phase inversion wavefield reconstruction robertsson applied geoscience wavefield geophysics fwi reconstruction exploration geophysicist 10...

... on the computation of frequency- Conventional methods to solve the time-harmonic elastic wave equa- domain solutions from time-domain solvers (Nihei and Li, 2007; Sir- tions usually rely on either direct solvers or iterative solvers. The gue et al., 2008), which takes bene t on the reliability and good scaling...

... covering spatial domains of moderate size, the later should be the approach of choice for sparse node acquisitions covering large domains (more than 50 millions of unknowns). Fast convergence of iterative solvers for Helmholtz problems remains however challenging in high frequency regime due to the non...

... of freedom. Unlike most of uncertainty quantification methodologies that use expensive forward solvers, we speed up our computations by using a numerically exact local acoustic solver. Presentation Date: Tuesday, September 17, 2019 Session Start Time: 1:50 PM Presentation Start Time: 3:05 PM Location...

... ABSTRACT A feasibility study on 3D frequency-domain anisotropic elastic wave modeling is conducted. The spectral element method is applied to discretize the 3D frequency-domain anisotropic elastic wave equation and the linear system is solved by parallel direct solvers, MUMPS andWSMP. A hybrid...

... geological scenarios. Such accuracy depends on the correctness of the anisotropic velocity model and on the numerical method for computing traveltimes. This work describes a new high-order fast-sweeping eikonal solver for q-SV waves in 3D TI media with emphasis on media with a vertical axis of symmetry. We...

... sparse, irregularly sampled data, containing pressure fields and two orders of its spatial derivatives, to retrieve the desired regularly-sampled, dense data. Here, we employ a prior-knowledge-based, data dependent sampling scheme, together with a consistent preconditioning for the solver, that aims...

... of the Helmholtz equation. Memory requirements for direct solvers are often prohibitively large in three dimensions, and this limited the examples in the literature to two dimensions. We present an algorithm that uses iterative Helmholtz solvers as a blackbox to solve the least-squares problem corresponding to 3D...

... ABSTRACT We introduce a novel idea, the WaveHoltz iteration, for solving the Helmholtz equation inspired by recent work on exact controllability (EC) methods. As in EC methods our method make use of time domain methods for wave equations to design frequency domain Helmholtz solvers but unlike...

... ABSTRACT A 3D finite-element time-domain (FETD) forward modelling solver is applied to synthesizing transient electromagnetics excited by a grounded-wire source. This FETD solver can deal with realistic transmitting waveforms and complex-shaped sources caused by topography. For a half-space...

... Time: 4:45 PM Location: 301B Presentation Type: Oral modeling & simulation field survey model construction enhanced oil recovery annual meeting upstream oil & gas site model enhanced recovery conductivity model solver reservoir model monitoring reservoir interval reservoir...

... Date: Wednesday, September 18, 2019 Session Start Time: 1:50 PM Presentation Start Time: 3:05 PM Location: 304A Presentation Type: Oral helmholtz equation solver memory consumption annual meeting upstream oil & gas dispersion error reservoir characterization factorization...

...-parameter inversion, however, this method is computationally expensive. In this study, we model AVO using a coupled elastic-acoustic local solver to model the wavefields and find that the amplitude of the reflectiongenerated by the local solver can be used to invert material properties at a reflector...

... We compare the performance of two acoustic solvers in the framework of frequency-domain full-waveform inversion. Using a realistic 3D marine model, we conduct a series of numerical experiments varying the number of nodes and sources taken from a typical 3D seismic acquisition scenario. When...

.... Biondi , 2014 , Joint full-waveform inversion of time-lapse seismic data sets : 84th Annual International Meeting, SEG , Expanded Abstracts , 1 – 5 , 10.1190/segam2014-0962.1 . Malcolm , A. , and B. Willemsen , 2017 , Rapid 4d FWI using a local solver : The Leading...