Title: Q-compensated reverse-time migration using a new time-domain viscoacoustic wave equation
Abstract:We derive a new time-domain complex-valued wave equation for viscoacoustic modeling and imaging. Starting from the frequency-domain viscoacoustic wave equation, we use a second-order polynomial to app...We derive a new time-domain complex-valued wave equation for viscoacoustic modeling and imaging. Starting from the frequency-domain viscoacoustic wave equation, we use a second-order polynomial to approximate the dispersion term and a pseudo-differential operator to approximate the dissipation term. With these two approximations, we transform the frequency-domain viscoacoustic wave equation to the time domain. Due to the introduction of an imaginary unit in the dispersion approximation, the new wave equation is complex-valued, which is similar to the time-dependent Schrödinger equation. The advantages of the proposed viscoacoustic wave equation include (1) dispersion and dissipation effects are separated naturally, (2) quality factor Q is explicitly incorporated in the wave equation, and (3) it can be solved using time matching and avoids solving a large linear system as the frequency-domain approaches. By flipping the sign of the dissipation term, the phase dispersion and amplitude loss can be corrected during wave-field back-propagation, which is important to image sub-surface reflectors with accurate kinematic and dynamic information. Since both source and receiver wavefields are analytical functions, we can explicitly separate the extrapolated wavefields into up- and down-going components, and apply a causal cross-correlation imaging condition to produce reflectivity images.Read More
Publication Year: 2019
Publication Date: 2019-06-05
Language: en
Type: article
Indexed In: ['crossref']
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