A shot domain offset vector tile optimization stack approach based on depth migration angle gather focal-beam analysis
TANG Cong1, FU Liyun2, CHEN Kang1, XIAO Han3, ZENG Ming1, MA Zhichao4
1. Research Institute of Exploration and Development, Southwest Oil & Gas Field Company, PetroChina, Chengdu, Sichuan 610041, China; 2. Key Laboratory of Deep Oil and Gas, China University of Petroleum(EastChina), Qingdao, Shandong 266580, China; 3. Chuanzhong Oil & Gas Production Plant, PetroChina Southwest Oil & Gasfield Company, Suining, Sichuan 629000, China; 4. China National Oil and Gas Exploration and Development Company Ltd, Beijing 100034, China
Abstract：Fault blocks and high-steep structures are developed in tectonic complicated areas. Compared with gentle formation，the high-steep tectonic areas are characterized by limited seismic illumination and low signal-to-noise ratio of seismic data. Therefore，the participation of fully biased data in stacking is adverse to improving imaging signal-noise ratio. Due to the difference in regional structural characteristics，the reflections corresponding to different high-steep tectonic zones are directional，and the reflection seismic phases of different offset (i.e.，incident angle) segments have obvious regional characteristics. This paper divides depth migration angle gathers into shot domain offset vector tile (SOVT)，thus effectively separating the depth migration data with different dip angles interfaces. The focal-beam analysis method is employed to analyze the signal focusing properties of SOVT stacked sections. Then，the weighted optimization stacking of the SOVT profile is performed based on its imaging sharpness attribute to highlight the effective signals and improve the imaging signal-noise ratio on the high-steep interface. The effectiveness of the proposed method is verified through the theoretical model and real data test. Meanwhile，the proposed method can be operated relying on the depth migration module of commercial software with only a few extra calculations required，which is suitable for industrial applications.
GUITTON A.Shot-profile migration of multiple reflections[C].SEG Technical Program Expanded Abstracts，2002，21：1296-1299.
[2]
LIU Y，CHANG X，JIN D G，et al.Reverse time migration of multiples for subsalt imaging[J].Geophy-sics，2011，76(5)：WB209-WB216.
[3]
曲英铭，魏哲枫，刘畅，等.面向高陡构造的黏声棱柱波逆时偏移[J].石油地球物理勘探，2020，55(4)：793-803.QU Yingming，WEI Zhefeng，LIU Chang，et al.Visco-acoustic reverse time migration of prismatic wave for steeply dipped structures[J].Oil Geophysical Prospecting，2020，55(4)：793-803.
[4]
秦宁，王常波，梁鸿贤，等.一次波和层间多次波联合成像方法[J].石油地球物理勘探，2022，57(6)：1375-1383.QIN Ning， WANG Changbo， LIANG Hongxian，et al.Joint imaging method of primaries and internal multiples[J].Oil Geophysical Prospecting，2022，57(6)：1375-1383.
[5]
LU L，VINCENT E，JI X.Imaging diffractors using wave-equation migration[J].Geophysics，2016，81(6)：S459-S468.
[6]
ZHANG J，WANG W，WANG S，et al.Optimized Chebyshev Fourier migration： A wide-angle dual-domain method for media with strong velocity contrasts[J].Geophysics，2010，75(2)：S23-S34.
[7]
TANG C，FU L，PAN W，et al.Optimized Pseudo-Padé Fourier migrator in terms of propagation angles[J].IEEE Access，2020，8：32054-32065.
[8]
杜启振，朱钇同，张明强，等.叠前逆时深度偏移低频噪声压制策略研究[J].地球物理学报，2013，56(7)：2391-2401.DU Qizhen，ZHU Yitong，ZHANG Mingqiang，et al.A study on the strategy of low wavenumber noise suppression for prestack reverse-time depth migration[J].Chinese Journal of Geophysics，2013，56(7)：2391-2401.
[9]
张大洲，魏石磊，熊章强.基于正反波场对比的逆时偏移假象分析[J].石油地球物理勘探，2014，49(3)：517-522，545.ZhANG Dazhou，WEI Shilei，XIONG Zhangqiang.Artifacts analysis of reverse time migration based on comparison between forward and reverse wave fields[J].Oil Geophysical Prospecting，2014，49(3)：517-522，545.
[10]
ZHANG Y，SUN J，GRAY S.Reverse-time migration： Amplitude and implementation issues[C].SEG Technical Program Expanded Abstracts，2007，26：2145-2149.
[11]
王晓毅，张江杰，许宏桥，等.基于Poynting矢量行波分离的最小二乘逆时偏移[J].地球物理学报，2021，64(2)：645-655.WANG Xiaoyi，ZHANG Jiangjie，XU Hongqiao，et al.Least-squares reverse time migration with wavefield decomposition based on the Poynting vector[J].Chinese Journal of Geophysics，2021，64(2)：645-655.
[12]
赵贤正，刘国昌，史原鹏，等.基于局部相似属性的数据依赖地震照明分析方法[J].石油地球物理勘探，2016，51(6)：1062-1068.ZHAO Xianzheng，LIU Guochang，SHI Yuanpeng，et al.Seismic illumination analysis with local similarity[J].Oil Geophysical Prospecting，2016，51(6)：1062-1068.
[13]
陈学强，王彦峰，吕景峰，等.库车坳陷复杂山地地震采集适用技术及应用效果[J].石油地球物理勘探，2022，57(4)：806-814.CHEN Xueqiang，WANG Yanfeng，LYU Jingfeng， et al.Seismic exploration technologies and applications in complex mountain areas of Kuqa Depression[J].Oil Geophysical Prospecting，2022，57(4)：806-814.
[14]
WU R S，CHEN L.Directional illumination analysis using beamlet decomposition and propagation[J].Geo-physics，2006，71(4)：S147-S159.
[15]
BERKHOUT A J.Pushing the limits of seismic imaging，part Ⅰ： prestack migration in terms of double dynamic focusing[J].Geophysics，1997，62(3)：937-953.
[16]
BERKHOUT A J.Pushing the limits of seismic imaging， part Ⅱ：Integration of prestack migration，velocity estimation，and AVO analysis[J].Geophysics，1997，62(3)：954-969.
[17]
WEI W，FU L，BLACQUIÈRE G.Fast multifrequency focal beam analysis for 3D seismic acquisition geometry[J].Geophysics，2012，77(2)：P11-P21.
[18]
李庆忠.走向精确勘探的道路[M].北京：石油工业出版社，1993.
[19]
徐雷良， 宋智强.南疆沙漠区超深层高密度地震采集方法[J].石油地球物理勘探，2023，58(1)：83-92.XU Leiliang，SONG Zhiqiang.Ultra deep and high- density seismic acquisition method in desert area of South Xinjiang[J].Oil Geophysical Prospecting，2023，58(1)： 83-92.
[20]
王晓阳，张晓斌，赵晓红，等.四川盆地复杂地表地震采集关键技术及其应用效果[J].天然气工业，2021，41(7)：15-23.WANG Xiaoyang，ZHANG Xiaobin，ZHAO Xiaohong， et al.Key technologies for complex surface seismic acquisition in the Sichuan Basin and their application effect[J].Natural Gas Industry，2021，41(7)：15-23
[21]
BERKHOUT A J，ONGKIEHONG L，VOLKER A W F， et al.Comprehensive assessment of seismic acquisition geometries by focal beams—Part Ⅰ：Theore-tical considerations[J].Geophysics，2001，66(3)：911-917.
[22]
常紫娟，魏伟，符力耘，等.“宽频带、宽方位和高密度”陆上三维地震观测系统聚焦分辨率分析[J].地球物理学报，2020，63(10)：3868-3885.CHANG Zijuan，WEI Wei，FU Liyun，et al.Focal beam resolution analysis of wide-band，wide-azimuth and high-density land 3D seismic acquisition geometries[J].Chinese Journal of Geophysics，2020，63(10)：3868-3885.
[23]
SAFAR M H.On the lateral resolution achieved by Kirchhoff migration[J].Geophysics，1985，50(7)：1091-1099.
[24]
SCHOENBERGER M.Resolution comparison of minimum-phase and zero-phase signals[J].Geophy-sics， 1974，39(6)：826-833.
