This paper presents an overview and a detailed description of the key logic steps mathematical-physics framework behind development practical algorithms for seismic exploration derived from inverse scattering series.

Great advances have been made in distributed acoustic sensing (DAS) vertical seismic profile (VSP) data acquisition hardware and software. Here, we capture a quantitative assessment of the quality DAS at single point time. We apply comprehensive testing methods to determine reliability its suitability as supplement geophone or gain access wells where it would be difficult deploy geophones. The test measurements are on data, which were collected same time well. analyze first breaks for...

The plight of Africa's AIDS orphans has reached crisis proportions, and the international community is beginning to mobilize at family, community, national, levels. Despite these encouraging efforts, response inadequate, increased attention action are needed. authors suggest that adoption, although a small temporary solution, may fit within framework being used as global working model. Issues surrounding such racism, racial cultural identity development, waiting children in U.S. public child...

Understanding the strengths and limitations of rapidly advancing distributed acoustic sensing (DAS) technology used for recording vertical seismic profile (VSP) data is achieved by comparing DAS geophone sets using both compressional-wave (P-wave) shear-wave (S-wave) VSP their corresponding geophysical answer products. We validate kinematics (time) dynamics (amplitude) examining extracted slowness values, response-to-incident angles, corridor stacks, common-depth-point (CDP) transforms. For...

Coherent noise may be removed from seismic data by first making an approximate model of the noise, then producing even better estimation adaptively matching modeled to data. This modified subtracted data, eliminating most coherent noise. The success this approach depends both on how well initial matches true and adaptive in modifying prediction match step is complicated presence signal other In article, interest surface-related multiples, although types with approach.

Abstract We consider the usual linear elastodynamics equations augmented with evolution for viscoelastic internal stresses. A fully discrete approximation is defined, based on a spatially symmetric or non‐symmetric interior penalty discontinuous Galerkin finite element method, and displacement‐velocity centred difference time discretisation. An priori error estimate given but only main ideas in proof of are reported here due to large number (mostly technical) estimates that required. The...

Recent applications of 2D and 3D turning-ray tomography show that near-surface velocities are important for structural imaging reservoir characterization. For imaging, we used to estimate the static corrections followed by prestack time migration depth migration. Two-dimensional acoustic finite-difference modeling illustrates wave-equation is very sensitive velocities. Field data demonstrate helps produce superior images in complex geologic settings. When velocity model integrated into a...

We consider discrete schemes for a nonlinear model of non‐Fickian diffusion in viscoelastic polymers. The is motivated by, but not the same as, that proposed by Cohen, White, and Witelski SIAM J. Appl. Math., 55 (1995), pp. 348–368. spatial discretization effected with both symmetric nonsymmetric interior penalty discontinuous Galerkin finite element method, time Crank–Nicolson type. also discuss two means handling nonlinearity: either implicitly, which requires solution equations at each...

This article defines a novel spatial-temporal modelling and analysis methodology applied to systems biology case study, namely phase variation patterning in bacterial colony growth. We employ coloured stochastic Petri nets construct the model run simulations record development of circular colonies over time space. The simulation output is visualised 2D, sector-like patterns are automatically detected analysed. Space modelled using 2.5 dimensions considering both rectangular geometry, effects...

We give a space-time Galerkin finite element discretization of the linear quasistatic compressible viscoelasticity problem as described by an elliptic partial differential equation with Volterra (memory) term. The consists continuous piecewise approximation in space discontinuous constant or time. derive priori maximum energy-error estimate exploiting "orthogonality" and data-stability related discrete backward problem. Illustrative numerical experiments are also included, is brief...

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2002New approaches to deghosting towed‐streamer and ocean‐bottom pressure measurementsAuthors: A. B. WegleinS. ShawK. H. MatsonJ. L. SheimanR. StoltT. TanA. OsenG. P. CorreaK. InnanenZ. GuoJ. ZhangA. WegleinUniversity of Houston, TX, S. ShawBP, K. MatsonBP, J. SheimanShell, R. StoltConoco, Ponca City, OK, T. TanShell, OsenStatoil, Stavanger, Norway, G. CorreaUniversity InnanenUniversity British Columbia, Vancouver, BC, Z....

Maxwell's equations in a bounded Debye medium are formulated terms of the standard partial differential electromagnetism with Volterra-type history dependence polarization on electric field intensity. This leads to memory. We make correspondence between this type constitutive law and hereditary integral laws from linear viscoelasticity, we then able apply known results viscoelasticity theory Maxwell system. In particular, can show long-time stability by shunning Gronwall's lemma estimating...

This work presents the depth calibration results of two independently conducted distributed acoustic sensing (DAS) vertical seismic profile (VSP) field trials. It describes methods applied and shows that, contingent upon accuracy well completion log, good accuracies in sub-meter range are attainable. Moreover, discrepancies analyzed between a conventional wireline VSP DAS that were recorded same at time; analysis depths can be matched accurately with geophone using solely points known along...

SUMMARY We revisit a method originally introduced by Werder et al. (in Comput. Methods Appl. Mech. Engrg., 190:6685–6708, 2001) for temporally discontinuous Galerkin FEMs applied to parabolic partial differential equation. In that approach, block systems arise because of the coupling spatial through inner products temporal basis functions. If finite element space is dimension D and polynomials degree r are used in time, system has ( + 1) usually regarded as being too large when > 1. found...

The problem characterizing nonageing linear isothermal quasi-static isotropic compressible solid viscoelasticity in the time interval [0,T] is described. This essentially a Volterra equation of second kind arrived at by adding smooth fading memory to elliptic elasticity equations. We analyze errors resulting from replacing relaxation functions with practical approximations, semidiscrete finite element approximation, and fully discrete scheme derived hereditary integral trapezoidal rule for...

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2000Imaging and inversion at depth without a velocity model: Theory, concepts initial evaluationAuthors: A. B. WegleinK. H. MatsonD. J. FosterP. M. CarvalhoD. CorriganS. ShawA. WegleinArco, Plano, Texas, K. MatsonArco, D. FosterArco, P. CarvalhoPetrobras SA, Rio de Janeiro, Brazil, CorriganArco, S. ShawArco, Texashttps://doi.org/10.1190/1.1815555 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack...

PreviousNext No AccessSEG Technical Program Expanded Abstracts 2001An inverse‐scattering sub‐series for predicting the spatial location of reflectors without precise reference medium and wave velocityAuthors: Arthur B. WegleinDouglas J. FosterKenneth H. MatsonSimon A. ShawPaulo M. CarvalhoDennis CorriganArthur WegleinUniversity Houston, TX, Douglas FosterPhillips Petroleum, Bartlesville, OK, Kenneth MatsonPhillips Simon ShawBP, Paulo CarvalhoPetrobras SA, Rio de Janeiro, Brazil, Dennis...

Abstract. Non-invasive detection, localization and characterization of an arterial stenosis (a blockage or partial in the artery) continues to be important problem medicine. Partial stenoses are known generate disturbances blood flow which shear waves chest cavity. We examine a one-dimensional viscoelastic model that incorporates Kelvin–Voigt damping internal variables, develop proof-of-concept methodology using simulated data. first estimation procedure for material parameters. use this...