1. School of Geosciences, China University of Petroleum(East China), Qingdao, Shandong 266580, China; 2. Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266580, China; 3. Geophysical Research Institute, Shengli Oil Field Branch Co., SINOPEC, Dongying, Shandong 257022, China
Abstract：When there are high impedence layer above and below a reservoir, strong reflections will shield reservoir reflection information on seismic sections.Therefore, we propose in this paper a dynamic matching pursuit method based on local frequency constraints to identify and separate strong reflections.Considering the "negative frequency" phenomenon of instantaneous frequency, we introduce local frequency to constrain the search range of the optimal atom of the dynamic matching pursuit algorithm.The local frequency is reasonable for the signal calculation, which can be used to identify the seismic wavelet that matches best the strong reflection.Using the local frequency and instantaneous phase information at the strong reflection position as a priori information, a dynamic waveform library is constructed to search for the wavelet that matches best the strong reflection.The strong reflection suppression coefficient is determined by signal tests to ensure that the equilibrium energy is consistent with the background energy after stripping strong reflection.This is helpful for picking up the reflection information of reservoirs and achieving reservoir characterization.The feasibility of the proposed method is verified by constructing model data with high impedence layer.Finally, the proposed method is applied to field data, which weakens strong reflection interference and highlights weak reflection.
凌云研究组.应用振幅的调谐作用探测地层厚度小于1/4波长地质目标[J].石油地球物理勘探, 2003, 38(3):268-274.LING Yun Research Group.Application of amplitude tuning in surveying geologic target thickness less than 1/4 wavelength[J].Oil Geophysical Prospecting, 2003, 38(3):268-274.
[2]
Widess M B.How thin is a thin bed?[J].Geophysics, 1973, 38(6):1176-1180.
[3]
张在金, 张军华, 李军, 等.煤系地层地震强反射剥离方法研究及低频伴影分析[J].石油地球物理勘探, 2016, 51(2):376-383.ZHANG Zaijin, ZHANG Junhua, LI Jun, et al.A method for stripping coal seam strong reflection and low-frequency shadow analysis[J].Oil Geophysical Prospecting, 2016, 51(2):376-383.
[4]
赵卫军, 支东明, 党玉芳, 等.准噶尔盆地陆西地区侏罗系西山窑组顶界不整合结构特征及其与油气关系[J].新疆地质, 2007, 25(1):92-95.ZHAO Weijun, ZHI Dongming, DANG Yufang, et al.Trait of unconformity structure and its relation with oil and gas at Xishanyaozu in Jurassic at Luxi Area in Junggar Basin[J].Xinjiang Geology, 2007, 25(1):92-95.
[5]
张志敏.青南洼陷古近系地震沉积学研究[D].山东东营:中国石油大学(华东), 2009.ZHANG Zhimin.The Study of Seismic Sedimentology of Paleogene in Qing-Nan Sag[D].China University of Petroleum(East China), Dongying, Shandong, 2009.
[6]
Mallat S G, Zhang Z.Matching-pursuit with time frequency dictionaries[J].IEEE Transactions on Signal Processing, 1993, 41(12):3397-3415.
[7]
Liu J, Wu Y, Han D, et al.Time-frequency decomposition based on Ricker wavelet[C].SEG Technical Program Expanded Abstracts, 2004, 23:1937-1940.
[8]
Liu J, Marfurt K J.Matching pursuit decomposition using Morlet wavelets[C].SEG Technical Program Expanded Abstracts, 2005, 24:786-789.
[9]
宋维琪, 朱卫星, 孙英杰.复数子波匹配追踪算法识别薄层砂体[J].地球物理学进展, 2007, 22(6):1796-1801.SONG Weiqi, ZHU Weixing, SUN Yingjie.Identify bed layer sandbody by complex wavelet matching algorithm[J].Progress in Geophysics, 2007, 22(6):1796-1801.
[10]
杨昊, 郑晓东, 李劲松, 等.基于匹配追踪的薄层自动解释方法[J].石油地球物理勘探, 2013, 48(3):429-435.YANG Hao, ZHENG Xiaodong, LI Jinsong, et al.Thin-bed automatic interpretation based on matching pursuit[J].Oil Geophysical Prospecting, 2013, 48(3):429-435.
[11]
张繁昌, 李传辉, 印兴耀.三角洲砂岩尖灭线的地震匹配追踪瞬时谱识别方法[J].石油地球物理勘探, 2012, 47(1):82-88.ZHANG Fanchang, LI Chuanhui, YIN Xingyao.Delta fringe line recognition based on seismic matching pursuit instantaneous spectral characteristics[J].Oil Geophysical Prospecting, 2012, 47(1):82-88.
[12]
李海山, 杨午阳, 田军, 等.匹配追踪煤层强反射分离方法[J].石油地球物理勘探, 2014, 49(5):866-870.LI Hhaishan, YANG Wuyang, TIAN Jun, et al.Coal seam strong reflection separation with matching pursuit[J].Oil Geophysical Prospecting, 2014, 49(5):866-870.
邓志文, 赵贤正, 陈雨红, 等.自适应波形多道匹配追踪断层识别技术[J].石油地球物理勘探, 2017, 52(3):532-537.DENG Zhiwen, ZHAO Xianzheng, CHEN Yuhong, et al.Fault identification based on multichannel adaptive waveforms matching pursuit[J].Oil Geophysical Prospecting, 2017, 52(3):532-537.
[16]
李传辉.地震信号快速匹配追踪分解及瞬时谱分析[D].山东青岛:中国石油大学(华东), 2012.LI Chuanhui.Fast Matching Pursuit Decomposition and Instantaneous Spectral Analysis of Seismic Signals[D].China University of Petroleum(East China), Qingdao, Shandong, 2012.
[17]
Taner M T, Koehler F, Sheriff R E.Complex seismic trace analysis[J].Geophysics, 1979, 44(6):1041-1063.
[18]
Barnes A E.The calculation of instantaneous frequency and instantaneous bandwidth[J].Geophysics, 1992, 57(11):1520-1524.
