Variable “wavelet” simulated imaging method based on illumination compensation
JIAO Junfeng1, ZHAO Aiguo2, LIAN Ximeng2, CUI Qinghui2, SUN Chengyu1, WU Han3
1. School of Geosciences, China University of Petroleum(East China), Qingdao, Shandong 266580; 2. Geophysical Research Institute, Shengli Oilfield Branch Co., SINOPEC, Dongying, Shandong 257022; 3. School of Earth Sciencesand Engineering, Sun Yat-Sen University, Zhuhai, Guangdong 519080
Abstract：Currently prestack depth migration is the key technology of high-precision seismic imaging. For a given velocity model, the traditional method is to solve the wave equation for wavefield forward modeling first, and then do prestack migration imaging for the forward wavefield. This method features low computational efficiency and high requirements for hardware. At present, the simulated prestack depth migration method based on an imaging operator does not need wavefield forward modeling and migration processing with high computational efficiency. However, there are some problems, such as inconsistency of the energy distribution with the actual situation, serious zonal reconstruction division, and incorrect imaging waveform. To improve the effect of simulated prestack migration imaging algorithms, a variable "wavelet" simulated prestack depth migration imaging method based on illumination com-pensation is proposed in this paper. This method first calculates the ray path according to the acquisition geometry, adopts the unit impulse instead of the point spread function to construct the direct imaging operator in the wavenum-ber domain, and acts as the imaging operator on the reflection coefficient model. Then, the imaging results in the simulated depth domain are obtained by unsteady convolution in the spatial domain, which solves the problem that the waveform cannot change spatially in the simulated depth imaging. Through the superposition of multi-point simulation imaging results under the action of unit impulse, the problems of spatial energy difference and illumination inability in individual areas are addressed. This method not only retains the advantage of the fast calculation speed of the original algorithm but also tackles the problems of energy distribution and "wavelet" space variation. Model test proves that the imaging results of this method are accurate, which can provide more accurate references for the selection of acquisition geometry and seismic imaging.
MICIKEVICIUS P. 3D finite difference computation on GPUs using CUDA[C]. Proceedings of 2nd Workshop on General Purpose Processing on Graphics Processing Units, Association for Computing Machinery, Washington D C, 2009, 79-84.
[2]
李博, 刘红伟, 刘国峰, 等. 地震叠前逆时偏移算法的CPU/GPU实施对策[J]. 地球物理学报, 2010, 53(12):2938-2943.LI Bo, LIU Hongwei, LIU Guofeng, et al. Computational strategy of seismic pre-stack reverse time migration on CPU/GPU[J]. Chinese Journal of Geophysics, 2010, 53(12):2938-2943.
[3]
刘守伟, 王华忠, 陈生昌, 等. 三维逆时偏移GPU/CPU机群实现方案研究[J]. 地球物理学报, 2013, 56(10):3487-3496.LIU Shouwei, WANG Huazhong, CHEN Shengchang, et al. Implementation strategy of 3D reverse time migration on GPU/CPU clusters[J]. Chinese Journal of Geophysics, 2013, 56(10):3487-3496.
[4]
FOLTINEK D, EATON D, MAHOVSKY J, et al. Industrial scale reverse time migration on GPU hardware[C]. SEG Technical Program Expanded Abstracts, 2009, 28:2789-2793.
[5]
GELIUS L J and STAMNES J J. Diffraction Tomagraphy imaging:Potentials and problems//Scattering in Volumes and Surfaces[M]. Elsevier, Amsterdam, 1990.
[6]
GELIUS L J, JOHANSEN I, SPONHEIM N, et al. A generalized diffraction tomography algorithm[J]. The Journal of the Acoustical Society of America, 1991, 89(2):523-528.
[7]
GELIUS L J, LECOMTE I, TABTI H. Analysis of the resolution function in seismic prestack depth imaging[J]. Geophysical Prospecting, 2002, 50(5):505-515.
[8]
HAMRAN S E, LECOMTE I. Local plane-wavenumber diffraction tomography in heterogeneous back-grounds, Part I:Theory[J]. Journal of Seismic Exploration, 1993, 2(2):133-146.
[9]
SETHIAN J A. A fast marching level set method for monotonically advancing fronts[J]. Proceedings of the National Academy of Sciences, 1996, 93(4):1591-1595.
[10]
张雪建, 梁锋, 王桂玲. 深度域合成地震记录的制作方法研究[J]. 石油地球物理勘探, 2000, 35(3):377-380, 385.ZHANG Xuejian, LIANG Feng, WANG Guiling. A method for synthesizing seismorgram in depth domain[J]. Oil Geophysical Prospecting, 2000, 35(3):377-380, 385.
[11]
LECOMTE I, GELIUS L J. Have a look at the resolution of prestack migration for any model, survey and wavefields[C]. SEG Technical Program Expanded Abstrcats, 1998, 17:1112-1115.
[12]
LECOMTE I, HAMRAN S E, TABTI H, et al. New insights in migration through analogies between generalized diffraction tomography and synthetic aperture radar[C]. SEG Technical Program Expanded Abstracts, 2001, 20:1111-1114.
[13]
LECOMTE I. Resolution and illumination analyses in PSDM:A ray-based approach[J]. The Leading Edge, 2008, 27(5):650-663.
[14]
LECOMTE I, HAMRAN S E, GELIUS L J. Improving Lirchhoff migration with repeated local planewave imaging? A SAR-inspired signal-processing approach in prestack depth imaging[J]. Geophysical Prospecting, 2005, 53(6):767-785.
[15]
张金陵, 徐美茹, 叶月明, 等. 利用点扩散函数的深度域地震记录合成方法[J]. 石油地球物理勘探, 2019, 54(4):875-881.ZHANG Jinling, XU Meiru, YE Yueming, et al. Seismogram synthetizing in the depth-domain with point spread function[J]. Oil Geophysical Prospecting, 2019, 54(4):875-881.
[16]
吴涵, 廉西猛, 孙成禹, 等. 叠前深度偏移地震记录直接模拟方法[J]. 石油地球物理勘探, 2020, 55(4):747-753.WU Han, LIAN Ximeng, SUN Chengyu, et al. Research on direct simulation to seismic record of prestack depth migration[J]. Oil Geophysical Prospecting, 2020, 55(4):747-753.
[17]
段伟国, 毛伟建, 张庆臣, 等. 基于密度扰动的点扩散函数计算与三维深度域模拟成像[J]. 地球物理学报, 2022, 65(4):1402-1415.DUAN Weiguo, MAO Weijian, ZHANG Qingchen, et al. Computation of denisty perturbation based point spread function and simulation of migration image in 3D depth domain[J]. Chinese Journal of Geophysics, 2022, 65(4):1402-1415.
[18]
何惺华. 深度域地震资料若干问题初探[J]. 石油物探, 2004, 43(4):353-358.HE Xinghua. Discussion on seismic data of depth domain[J]. Geophysical Prospecting for Petroleum, 2004, 43(4):353-358,
[19]
林伯香, 胡中平, 薛诗桂. 利用变换深度域速度函数制作深度域合成地震记录[J]. 石油地球物理勘探, 2006, 41(6):640-643.LIN Boxiang, HU Zhongping, XUE Shigui. Using velocity function in transformed depth domain to make synthetic seismograph in depth domain[J]. Oil Geophysical Prospecting, 2006, 41(6):640-643.
[20]
樊中海, 胡渤, 宋吉杰, 等. 地震反演储层描述精度影响因素分析[J]. 石油地球物理勘探, 2022, 57(2):441-451.FAN Zhonghai, HU Bo, SONG Jijie, et al. Analysis of influencing factors in reservoir description accuracy by seismic inversion[J]. Oil Geophysical Prospecting, 2022, 57(2):441-451.
[21]
邵广周, 独婷, 吴华. 基于自适应震源子波提取与校正的瑞利波波形反演[J]. 石油地球物理勘探, 2022, 57(4):838-846.SHAO Guangzhou, DU Ting, WU Hua. Waveform inversion based on adaptive source wavelet extraction and correction for Rayleigh waves[J]. Oil Geophysical Prospecting, 2022, 57(4):838-846.
[22]
STAMNES J J. Waves in Focal Regions:Propagation, Diffraction and Focusing of Light, Sound and Water Waves[M]. Routledge, New York, 1986.
[23]
BEYLKIN G, ORISTAGLIO M, MILLER D. Spatial resolution of migration algorithms[C]. Proceedings of the 14th International Symposium on Acoustical Image, 1985, 155-167.
[24]
BEYLKIN G. Imaging of discontinuities in the inverse scattering problem by inversion of a causal generalized Radon transform[J]. Journal of Mathematical Physics, 1985, 26(1):99-108.
