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Convolution-based multi-scale envelope inversion

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Petroleum Science 2020年第2期17卷 352-362页

作者： Ding-Jin Liu jian-ping huang Zi-Ying Wang Sinopec Geophysical Research Institute Nanjing 211103JiangsuChina China University of Petroleum(East China) Qingdao 266580ShandongChina Pilot National Laboratory for Marine Science and Technology Qingdao 266571ShandongChina

Envelope inversion(El)is an efficient tool to mitigate the nonlinearity of conventional full waveform inversion(FWI)by utilizing the ultralow-frequency component in the seismic ***,the performance of envelope inversion depends on the frequency component and initial model to some *** improve the convergence ability and avoid the local minima issue,we propose a convolution-based envelope inversion method to update the low-wavenumber component of the velocity ***,the multi-scale inversion strategy(MCEI)is also incorporated to improve the inversion accuracy while guaranteeing the global *** success of this method relies on modifying the original envelope data to expand the overlap region between observed and modeled envelope data,which in turn expands the global minimum basin of misfit *** accurate low-wavenumber component of the velocity model provided by MCEI can be used as the migration model or an initial model for conventional *** numerical tests on simple layer model and complex BP 2004 model verify that the proposed method is more robust than El even when the initial model is coarse and the frequency component of data is high.

关键词： Full waveform inversion Multi-scale strategy Envelope inversion

Accurate simulations of pure-viscoacoustic wave propagation in tilted transversely isotropic media

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Petroleum Science 2024年第2期21卷 866-884页

作者： Qiang Mao jian-ping huang Xin-Ru Mu Ji-Dong Yang Yu-jian Zhang Geosciences Department China University of Petroleum(East China)Qingdao266580ShandongChina Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao266207ShandongChina

Forward modeling of seismic wave propagation is crucial for the realization of reverse time migration(RTM) and full waveform inversion(FWI) in attenuating transversely isotropic media. To describe the attenuation and anisotropy properties of subsurface media, the pure-viscoacoustic anisotropic wave equations are established for wavefield simulations, because they can provide clear and stable wavefields. However, due to the use of several approximations in deriving the wave equation and the introduction of a fractional Laplacian approximation in solving the derived equation, the wavefields simulated by the previous pure-viscoacoustic tilted transversely isotropic(TTI) wave equations has low accuracy. To accurately simulate wavefields in media with velocity anisotropy and attenuation anisotropy, we first derive a new pure-viscoacoustic TTI wave equation from the exact complex-valued dispersion formula in viscoelastic vertical transversely isotropic(VTI) media. Then, we present the hybrid finite-difference and low-rank decomposition(HFDLRD) method to accurately solve our proposed pure-viscoacoustic TTI wave equation. Theoretical analysis and numerical examples suggest that our pure-viscoacoustic TTI wave equation has higher accuracy than previous pure-viscoacoustic TTI wave equations in describing q P-wave kinematic and attenuation characteristics. Additionally, the numerical experiment in a simple two-layer model shows that the HFDLRD technique outperforms the hybrid finite-difference and pseudo-spectral(HFDPS) method in terms of accuracy of wavefield modeling.

关键词： Pure-viscoacoustic TTI wave equation Attenuation anisotropy Seismic modeling Low-rank decomposition method

3D elastic waveform modeling with an optimized equivalent staggered-grid finite-difference method

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Petroleum Science 2020年第4期17卷 967-989页

作者： Qiang Zou jian-ping huang Peng Yong Zhen-Chun Li School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina Tarim Oilfeld Branch CNPCKorla 841000XinjiangChina

Equivalent staggered-grid(ESG) as a new family of schemes has been utilized in seismic modeling,imaging,and ***,the Taylor series expansion is often applied to calculate finite-difference(FD) coefficients on spatial derivatives,but the simulation results suffer serious numerical dispersion on a large frequency *** develop an optimized equivalent staggered-grid(OESG) FD method that can simultaneously suppress temporal and spatial dispersion for solving the second-order system of the 3 D elastic wave *** the one hand,we consider the coupling relations between wave speeds and spatial derivatives in the elastic wave equation and give three sets of FD coefficients with respect to the P-wave,S-wave,and converted-wave(C-wave) *** the other hand,a novel plane wave solution for the 3 D elastic wave equation is derived from the matrix decomposition method to construct the time-space dispersion *** coefficients of the OESG method can be acquired by solving the new dispersion equations based on the Newton iteration ***,we construct a new objective function to analyze P-wave,S-wave,and C-wave dispersion concerning *** dispersion analyses show that the presented method produces less modeling errors than the traditional ESG *** synthetic examples demonstrate the effectiveness and superiority of the presented method.

关键词： 3D elastic wave equation Optimized equivalent staggered-grid Numerical dispersion Newton iteration method Plane wave solution

Overview of computation strategies on the dispersion analysis for explicit finite difference solution of acoustic wave equation

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Petroleum Science 2024年第4期21卷 2311-2328页

作者： jian-ping huang Wei-Ting Peng Ji-Dong Yang Lu-Feng Lou School of Geosciences China University of Petroleum(East China)Qingdao266580ShandongChina Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao266000ShandongChin

Finite-difference(FD)method is the most extensively employed numerical modeling ***,when using the FD method to simulate the seismic wave propagation,the large spatial or temporal sampling interval can lead to dispersion errors and numerical *** the FD scheme,the key factor in determining both dispersion errors and stability is the selection of the FD ***,How to obtain appropriate FD weights to guarantee a stable numerical modeling process with minimum dispersion error is *** FD weights computation strategies can be classified into three types based on different computational ideologies,window function strategy,optimization strategy,and Taylor expansion *** this paper,we provide a comprehensive overview of these three strategies by presenting their fundamental *** conduct a set of comparative analyses of their strengths and weaknesses through various analysis tests and numerical *** to these comparisons,we provide two potential research directions of this field:Firstly,the development of a computational strategy for FD weights that enhances stability;Secondly,obtaining FD weights that exhibit a wide bandwidth while minimizing dispersion errors.

关键词： Finite-difference scheme FD coefficients Dispersion error Forward modeling Numerical simulation

A computational method for wide-azimuth 3D dip-angle gathers using Gaussian beam migration

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Petroleum Science 2022年第5期19卷 2081-2094页

作者： Su-Bin Zhuang jian-ping huang Ji-Dong Yang Zhen-Chun Li School of Geosciences China University of Petroleum(East China)Qingdao266580ShandongChina

The dip-angle-domain common-image gather(DDCIG)is a key tool to separate the diffraction and reflection imaging *** with different spatial geometries produce different responses in *** with Kirchhoff migration,Gaussian beam migration(GBM)is more effective and robust to overcome the multipathing *** a ray-based method,it has explicit angle information naturally during the *** have developed a 3D DDCIG computational method using GBM,which obtain both the imaging result and angle-domain gathers with only one pass of *** angle-gather computation is based on geometrical optics,and multiple angle conversions are implemented under the rules of space geometry,which helps to avoid rounding errors and improve ***,the multi-azimuth joint presentation strategy is proposed to describe the characteristic of omnidirectional dip angles using a finite number of *** using a 2D model to illustrate application advantages of DDCIG,we apply the proposed method to two 3D models to test its feasibility and accuracy.A field data example further demonstrates the adaptability of our method to seismic imaging for a land survey.

关键词： Gaussian beam Dip-angle gathers 3D imaging Diffraction

An amplitude-preserved adaptive focused beam seismic migration method

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Petroleum Science 2015年第3期12卷 417-427页

作者： Ji-Dong Yang jian-ping huang Xin Wang Zhen-Chun Li School of Geoscience China University of PetroleumQingdao

Gaussian beam migration （GBM） is an effec- tive and robust depth seismic imaging method, which overcomes the disadvantage of Kirchhoff migration in imaging multiple arrivals and has no steep-dip limitation of one-way wave equation migration. However, its imaging quality depends on the initial beam parameters, which can make the beam width increase and wave-front spread with the propagation of the central ray, resulting in poor migration accuracy at depth, especially for exploration areas with complex geological structures. To address this problem, we present an adaptive focused beam method for shot-domain prestack depth migration. Using the infor- mation of the input smooth velocity field, we first derive an adaptive focused parameter, which makes a seismic beam focused along the whole central ray to enhance the wave- field construction accuracy in both the shallow and deep regions. Then we introduce this parameter into the GBM, which not only improves imaging quality of deep reflectors but also makes the shallow small-scale geological struc- tures well-defined. As well, using the amplitude-preserved extrapolation operator and deconvolution imaging condi- tion, the concept of amplitude-preserved imaging has been included in our method. Typical numerical examples and the field data processing results demonstrate the validity and adaptability of our method.

关键词： Keywords Gaussian beam Adaptive focused beam Amplitude-preserved migration Depth imaging

Target-oriented Gaussian beam migration using a modif ied ray tracing scheme

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Petroleum Science 2019年第6期16卷 1301-1319页

作者： Rui Zhang jian-ping huang Su-Bin Zhuang Zhen-Chun Li School of Geosciences China University of Petroleum(East China)Qingdao 266580China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China

For large-scale 3D seismic data,target-oriented reservoir imaging is more attractive than conventional full-volume migration,in terms of computation *** beam migration(GBM)is one of the most robust depth imaging method,which not only keeps the advantages of ray methods,such as high efficiency and flexibility,but also allows us to solve caustics and multipathing *** conventional Gaussian beam migration requires slant stack for prestack data,and ray tracing from beam center location to subsurface,which is not easy to be directly applied for target-oriented *** this paper,we modify the conventional Gaussian beam migration scheme,by shooting rays from subsurface image points to receivers to implement wavefield *** modification helps us to achieve a better subsurface illumination in complex structure and allows simple implementation for target reservoir ***,compared with the wavefi eld-based GBM,our method does not reconstruct the subsurface snapshots,which has higher *** the proposed method is not as efficient as the conventional Gaussian beam *** and field data examples demonstrate the validity and the target-oriented imaging capability of our method.

关键词： Gaussian beam migration Target-oriented imaging Illumination Ray tracing

Regularized least-squares migration of simultaneous-source seismic data with adaptive singular spectrum analysis

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Petroleum Science 2017年第1期14卷 61-74页

作者： Chuang Li jian-ping huang Zhen-Chun Li Rong-Rong Wang School of Geosciences China University of PetroleumQingdao 266580 Shandong China Hisense (Shandong) Refrigerator Co. Ltd HisenseQingdao 266580 Shandong China

Simultaneous-source acquisition has been recog- nized as an economic and efficient acquisition method, but the direct imaging of the simultaneous-source data produces migration artifacts because of the interference of adjacent sources. To overcome this problem, we propose the regularized least-squares reverse time migration method （RLSRTM） using the singular spectrum analysis technique that imposes sparseness constraints on the inverted model. Additionally, the difference spectrum theory of singular values is presented so that RLSRTM can be implemented adaptively to eliminate the migration artifacts. With numerical tests on a fiat layer model and a Marmousi model, we validate the superior imaging quality, efficiency and convergence of RLSRTM compared with LSRTM when dealing with simultaneoussource data, incomplete data and noisy data.

关键词： Least-squares migration Adaptive singularspectrum analysis Regularization Blended data

2D Q-compensated multi-component elastic Gaussian beam migration

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Petroleum Science 2023年第1期20卷 230-240页

作者： Chao Chen Ji-Dong Yang Xin-Ru Mu Zhen-Chun Li jian-ping huang China University of Petroleum(East China) Qingdao266580ShandongChina

Elastic waves are affected by viscoelasticity during the propagation through the Earth,resulting in energy attenuation and phase distortion,in turn resulting in low seismic imaging ***,viscoelasticity should be considered in seismic migration *** propose a Q compensated multicomponent elastic Gaussian beam migration(Q-EGBM)method to(1)separate the elastic-wave data into longitudinal(P)and transverse(S)waves to perform PP-wave and PS-wave imaging;(2)recover the amplitude loss caused by attenuation;(3)correct phase distortions caused by dispersion;(4)improve the resolution of migration *** this paper,to accomplish(2),(3),and(4),we derive complex-valued traveltimes in viscoelastic *** results of numerical experiments using a simple five-layer model and a sophisticated BP gas model show that the method presented here has significant advantages in recovering energy decay and correcting phase distortion,as well as significantly improving imaging resolution.

关键词： Q-compensated Viscoelastic Gaussian beam migration Multi-component Absorption attenuation