..., and their accuracy is verified by numerical calculation of different thicknesses in the weak impedance comparison model. The error between the exact value and the approximate value may be caused by the PP and PS reflection coefficients of the bottom interface. Our method shows a great relationship between the exact...

... sacchi qr decomposition svd upstream oil & gas reconstruction geophysics international exploration geophysicist matrix american association interpolation applied geoscience reservoir characterization approximation cur decomposition cur approximation society randomized qr...

... We propose a perturbation-based approximation for P- and S-wave traveltime in a transversely isotropic medium with a vertical symmetry axis (VTI). The perturbation coefficients in this approximation are derived directly from the implicit parametric offset-traveltime equation. The comparison...

... association energy 10 frequency characteristic approximation discrimination study media applied geoscience modeling society Study on fluid discrimination method based on prestack frequency-dispersion characteristics Li'en Bian*, Jun Ming, Yuxiu Wang, Qian Yu China National Offshore Oil Corporation...

... pa hydraulic fracturing media exploration geophysicist assumption reservoir characterization shale international thomsen fracture plane compliance applied geoscience approximation university gradient fracture compliance orthorhombic media Anisotropy parameters for fractured shales...

... simulation, and is superior to the conventional staggered-grid pseudospectral method in terms of accuracy. reservoir characterization society carcione modeling media international american association extrapolation attenuation fomel applied geoscience geophysics approximation journal...

... international upstream oil & gas vector decomposition characteristic shengchang chen school linear inversion reflectivity approximation Elastic reverse time migration without wavefield decomposition Daiguang Li* and Shengchang Chen School of Earth Sciences, ZheJiang University Summary Elastic...

... and shot selection. These workflow improvements have allowed us to significantly reduce the cost of applying LSRTM, while still generating high fidelity and physically meaningful results. reservoir characterization international selection approximation iteration hessian american association...

... variation relative the P-wave velocity of the undisturbed formation and the phase of the scattering wave reflects the positive and negative velocity variations under the Born approximation, which can be effectively utilized to invert formation alteration parameters from borehole acoustic waveform data...

... reservoir characterization approximation novel prestack basic pursuit upstream oil & gas applied geoscience exploration geophysicist 10 fatti approximation elastic parameter constraint correlation inversion prestack inversion objective function prestack basic pursuit inversion...

... on the solution of a rst-order differential equation in solution of the coupled set of equations is approximated with the time domain for the analytical wave eld. Such wave eld the Tal-Ezer s technique. Such challenge can therefore be ad- is separated into real and imaginary parts, and the resulting dressed...

... The elastic wave propagation is coupled in VTI media. Different approximations are used to obtain single wave equation, such as acoustic approximation and weak anisotropic approximation. In this paper, we start from the exact elastic wave phase velocities in VTI media, and propose an approximate...

...Extension of the kinematic approximations to the multilayered elastic orthorhombic medium Shibo Xu*, Kyoto University; Alexey Stovas, Norwegian University of Science and Technology Summary multilayered case. The extension can be successfully implemented for the multilayered ORT model without...

...Perturbation-based traveltime approximation from two acoustic VTI assumptions Shibo Xu*, Kyoto University; Alexey Stovas, Norwegian University of Science and Technology Summary three VTI models with a different set of anisotropy parameters. The numerical results could be taken as a We propose...

... phenomena in the ray beam. We use the 15° one-way wave method based on the high frequency approximation equation in the local ray beam for propagation, thus solution of wave equation and the finite difference overcoming the assumption of the high frequency numerical solution or mixed domain solution based...

... is nearly singular, the Newton direction becomes exces- because it requires inverting the Hessian operator. In addition, sively long such that the quadratic approximation implicitly the mis t is not necessarily quadratic, thus the exact Newton made when computing it ceases to hold. Much computational...

... in the Furthermore, such acquisition system makes it possible to record four- ocean-bottom acquisition, the FWI based on an elastic approximation component data through a combination of hydrophones and three- for the subsurface maybe worth the extra computational cost. component (3C) geophones. The information...

... with the presented technology the door towards the use of low-memory accelerators such as GPUs. reservoir characterization memory imprint gradient calculation geophysics upstream oil & gas seismic inversion full-waveform inversion inversion machine learning approximation randomized trace...

... on creating uncertainty estimates based on evaluation of the toward models which are not representative of the true subsurface, and posterior covariance matrix, which is approximately the inverse of numerical optimization techniques used in the inversion allow for only the Hessian near the minimum of the FWI...

... based on approximations of the conventional Gauss-Newton operator. We illustrate the latter aspect To overcome this issue, multi-scale hierarchical work ow are widely using the Marmousi model. used in practice, together with the use of accurate initial model build- ing tools such as stereotomography...