Due to the energy attenuation and phase distortion of seismic waves propagating in viscous media, it is difficult obtain high resolution amplitude preserved migration images without compensating effects. In this paper, we provide a reverse time (RTM) scheme based on viscoacoustic wave equation with fractional Laplacian operators compensate First, develop high-efficiency method for simulating propagation equation. Since independent number different Q values, numerical simulation examples show...

Least-squares reverse time migration (LSRTM) can provide higher quality images than conventional migration, which is helpful to image simultaneous-source data. However, it still faces the problems of crosstalk noise, great computation time, and storage requirement. We propose a new LSRTM approach by using excitation amplitude (EA) imaging condition suppress noise. Since only maximum or limited local amplitudes at each point corresponding travel step(s) need be saved, problem naturally...

The lack of low-frequency signals in seismic data makes the full-waveform inversion (FWI) procedure easily fall into local minima leading to unreliable results. To reconstruct missing more accurately and effectively, we have developed a data-driven recovery method based on deep learning from high-frequency signals. In our method, develop idea using basic patch build mapping recovery. Energy balancing patches are used prepare high- for training convolutional neural network (CNN) establish...

The traditional high-order staggered-grid finite-difference (SGFD) method has accuracy in space, but only the second-order time, which makes SGFD suffer from a large temporal dispersion error during long-distance wave propagation. This paper develops fourth- and sixth-order spatial arbitrary evenorder schemes to model isotropic elastic have smaller than scheme, thus allow larger time steps attain similar accuracy. developed are applied simulate quasi-stress–velocity equation (QWE) that is...

Simultaneous-source method is usually adopted, as one of the most efficient ways, to reduce computation cost full waveform inversion (FWI). Unfortunately, this facing with problem crosstalk noise, degrading quality results. To avoid problem, we propose an algorithm time–frequency hybrid-domain simultaneous-source FWI based on time-domain finite difference phase sensitive detection method. The harmonic sine functions different frequencies are used wavelet signals for sources within super...

Accurate estimation of source wavelet is crucial in a successful full-waveform inversion (FWI); however, it cannot be guaranteed the case real seismic data. We have developed time-domain source-independent elastic FWI using convolution-based objective function that was originally for acoustic FWI. applied new time window on reference traces to suppress noises induced by convolution and crosscorrelation operations. Also, we adopted [Formula: see text]-, Huber-, hybrid-norm functions improve...

Reverse time migration (RTM) in attenuating media should take absorption and dispersion effects into consideration. The latest proposed viscoacoustic wave equation with decoupled fractional Laplacians facilitates separate amplitude compensation phase correction [Formula: see text]-compensated RTM ([Formula: text]-RTM). However, intensive computation enormous storage requirements of text]-RTM prevent it from being extended practical application, especially for large-scale 2D or 3D cases....

Hanseniaspora uvarum is a prevalent yeast species in vineyards. However, its application grape wine fermentation remains limited. This study used culture-dependent and -independent approaches to investigate the dynamics of H. during spontaneous Cabernet Sauvignon grapes. The results revealed that constituted 77.49 % non-Saccharomyces population fermentation. An indigenous strain, QTX-C10, was isolated from 148 strains using multistep screening strategy. 1:1 co-inoculation QTX-C10 with...

Simultaneous source acquisition, which allows a temporal overlap between shot records, has significant advantages to improve data quality (e.g., denser shooting) and reduce acquisition cost efficient wide-azimuth shooting). We have developed novel shot-domain deblending approach for simultaneous shooting survey based on an inversion scheme. The inverse problem is formulated by introducing two convolution operators that can respectively destruct the signal interference solved...

Time-frequency analysis always plays a central role in the field of seismic processing due to advantage characterizing nonstationary signals. In this letter, we present novel technique for time-frequency based on high-order synchrosqueezing transform, which obtains more accurate instantaneous frequencies by using higher order approximations both amplitude and phase achieve highly energy-concentrated representation. A synthetic example is employed demonstrate validity proposed method...

Two staggered-grid finite-difference (SGFD) schemes with fourth- and sixth-order accuracies in time have been developed recently based on new SGFD stencils. The coefficients of the two are determined by a Taylor-series expansion (TE) approach, which is accurate only near zero wavenumber. We adopted same stencils minimizing errors between wavenumber responses operators first-order [Formula: see text] (wavenumber)-space operator least-squares (LS) sense. solved LS problems performing weighted...

SUMMARY It is difficult to separate additive random noise from spatially coherent signal using a rank-reduction (RR) method that based on the truncated singular value decomposition (TSVD) operation. This problem due mixture of and subspaces after TSVD drawback can be partially conquered damped RR (DRR) method, where values corresponding effective signals are adjusted via carefully designed damping operator. The operator works most powerfully in case small rank factor. However, for...

The [Formula: see text]-compensated viscoelastic reverse time migration ([Formula: text]-ERTM) method counteracts the subsurface quality-factor text]) filtering effect for attenuated multicomponent seismic data to produce high-quality migrated images. Compared with viscoacoustic text]-ARTM), text]-ERTM provides more informative geologic and structural characterization of subsurface, but it poses greater challenges on wavefield decomposition stabilization. On basis our previously proposed...

Abstract Full waveform inversion (FWI) is capable of generating high‐resolution subsurface parameter models, but it susceptible to cycle‐skipping when the data lack low‐frequency components. Unfortunately, such components (<5.0 Hz) are often tainted by noise in real seismic exploration, which hinders application FWI. To address this issue, we develop a novel self‐supervised extrapolation method that does not require labeled data, enabling neural networks be trained directly on data. In...

In real-world scenarios, the effectiveness of seismic denoising methods based on supervised learning (SL) is hindered by scarcity clean labeled data. A network trained synthetic data often struggles to adapt distinct feature distributions field To address this challenge, we develop an self-SL strategy that effectively attenuates various types noise using a single model. Our approach starts with warm-up phase pretrains artificially noisier-noisy pairs, enhancing its stability and ability...

Elastic full waveform inversion (FWI) is more suitable to process multicomponent seismic data and can provide subsurface medium information than acoustic FWI often with lower efficiency. Except for the parallel algorithms, source-encoding methods are usually adopted improve efficiency of FWI, but it includes crosstalk noise. Besides, additional source estimation process, critical a successful would counteract high-efficiency advantage algorithm. We propose an elastic source-independent...

SUMMARY Most researches on the Biot-squirt (BISQ) model are limited to poroelastic transverse isotropic (TI) media. Actually, poro-viscoelasticity and orthorhombic anisotropy closer realistic properties of many reservoir Therefore, we expand BISQ theory poro-viscoelastic media develop corresponding constitutive relation 3-D wave equations in time domain. Here, generalized Zener linear body is introduced describe relaxation effect solid skeleton, pore fluid assumed be saturated. The...

Abstract In this paper, the lattice Boltzmann method (LBM) is employed to simulate wave propagation in viscous media. LBM a kind of microscopic for modelling waves through tracking evolution states large number discrete particles. By choosing different relaxation times experiments and using spectrum ratio method, we can reveal relationship between quality factor Q parameter τ LBM. A two-dimensional (2D) homogeneous model two-layered are tested numerical experiments, results compared against...

Seismic migration can be formulated as an inverse problem, the model of which iteratively inverted via least-squares framework instead approximated by applying adjoint operator to observed data. Least-squares reverse time (LSRTM) has attracted more and attention in modern seismic imaging workflows because its exceptional performance obtaining high-resolution true-amplitude images fast development computational capability computing architecture. However, due a variety reasons, e.g.,...

Faced with the scarcity of clean label data in real scenarios, seismic denoising methods based on supervised learning (SL) often encounter performance limitations. Specifically, when a model trained synthetic is directly applied to field data, its would drastically decline due significant differences feature distributions between two. To address this challenge, we develop an effective self-supervised strategy. This strategy, while relying single network model, adeptly attenuates various...