... Dispersion curve inversion is a key step in obtaining the acoustic velocity of formations around wells and information evaluation. Traditional dispersion inversion methods, based on wellbore sound propagation theory, suffer from low efficiency and multimodality issues. Methods based on deep...

... P-wave dispersion (frequency dependent p-wave velocities) associated with fluid mobility in porous/permeable reservoirs can be measured in the frequency domain, and the results incorporated in standard Oil and Gas Exploration and Production scenarios where relative permeability of hydrocarbon vs...

... spatial numerical dispersion, which uses the Fourier transform to compute spatial derivatives accurately. Secondly, to suppress the time dispersion, we treat the acoustic wave equation as a harmonic oscillator differential equation and obtain its exact finite difference scheme by the source discretization...

... Measurements of dynamic elastic properties of shale exhibit dispersion at seismic frequencies as well as between seismic and ultrasonic frequencies. We point to various possible dispersion mechanisms, including viscoelasticity of bound water in the narrow pores associated with clays and squirt...

... Seismic waves propagating through the hydrocarbon reservoirs that are saturated with viscous fluid tend to act velocity dispersion and attenuation. To quantify the effects of fluid properties as well as pressure on seismic dispersion and attenuation characteristics, we performed the joint...

... government reservoir geomechanics prediction semi-quantitative prediction energy 10 attenuation applied geoscience dispersion south china sea deepwater frequency international interpretation Semi-quantitative prediction of hydrocarbon gas saturation in carbon dioxide enrichment areas...

... dispersion in both lateral and vertical directions. In addition, the impact on subsurface well design on gas saturations for extended injection/drainage cycles was investigated. Initial screening results used relative permeability parameters determined in a brine/hydrogen system derived from Yekta, 2018...

... Interpreting formation shear slowness from logging-while-drilling (LWD) quadrupole sonic dispersion data remains a challenge due to its nonasymptotic characteristics at low frequencies. We have developed a fully automated solution, i.e., machine learning enabled automatic quadrupole...

... between receivers of the sparse array. We invert the Rayleigh wave dispersion curves for the S-wave velocity structure beneath the array with additional constrains on layer boundaries derived from the P-wave model. An application on a sparse array in urban environment in The Hague, The Netherlands...

.... This process is often complicated by distortion of waveforms caused by frequency dependent attenuation and velocity dispersion. These difficulties can be overcome by using viscoelastic inversion of ultrasonic waveforms, which estimates velocities and attenuation factors of P and S waves by minimizing...

... equation modeling. These two FD methods adopt the same FD stencil using only the axial grid points to construct the 3D Laplace operator, which gives rise to obvious numerical dispersion and numerical anisotropy. In this paper, we derive how to use the off-axial grid points to approximate the 3D Laplace...

...-wave ultrasonic velocity data of dry and fluid-saturated rock under pressure loading conditions, so as to determine the pore-aspect-ratio spectrum through an inversion procedure. The inverted pore-aspect-ratio spectrum is input into the wave theory to predict the velocity dispersion of the rock...

... In the field of geophysical prospecting, the finitedifference (FD) method has always been an important numerical simulation algorithm. In order to suppress the dispersion of the FD scheme, many scholars have proposed various methods to optimize the coefficients of FD scheme. The operators of FD...

... fluid identification carbonate reservoir hadexun area seg international exposition fracture dispersion complex reservoir avozf inversion exploration geophysicist 10 inversion equation inversion method anisotropy Fluid identification and effective fractures prediction by combining AVOF...

... We experimentally measured elastic and inelastic parameters of two sandstones at dry and water saturated conditions with frequencies range from 2 Hz to 500 Hz. Data indicates that attenuation and velocity dispersion are strongly dependent on rock permeability and pore fluids, particularly...

... water saturation sandstone seg international exposition east china tongcheng han china university fluid flow p-wave velocity geophysics saturation dispersion P-wave attenuation in partially saturated sandstones with varying pressures Shubo Ren* and Tongcheng Han, China University...

... with real drilling noise. reservoir characterization well logging upstream oil & gas octupole mode drilling measurement artificial intelligence brenda jonathan higher-pole mode log analysis drilling data acquisition lwd slowness-frequency semblance map dispersion curve slowness...

... In this work, we consider changes in the degree of fracture connectivity to explore the effects that this parameter has on the seismic response in general and on Rayleigh wave velocity dispersion in particular. To this end, we apply a numerical upscaling method in a Monte-Carlo-type manner...

... layer (PML) absorbing boundary condition and a spatial variable density. We derive an analytical temporal extrapolation formula under the staggered-grid configuration. The analytical extrapolation formula ensures an absolutely stable simulation result without numerical dispersion in homogeneous media...

... ABSTRACT Considering the anisotropy of velocity and attenuation, we investigate the wavefield simulation of viscoacoustic wave in vertically transverse isotropic (VTI) attenuative media. The equations with decoupled amplitude dissipation and phase dispersion are derived based on the fractional...