Abstract:The seawater depth is a basis for OBC dual-sensor data summing.A seawater depth inversion method based on segmented data cross-bispectrum is proposed in combination with the time series higher-order statistics.First the auto-bispectrum and cross bispectrum of up-going and down-going wave field data are calculated from the segmented OBC data.Then the coherent cross-bispectrum and cross-correlation spectrum are calculated.Finally,the seawater depth is calculated and used for the OBC data summing.The OBC dual-sensor segmented data computation utilizes fully stacking characteristics,which increases the suppression of Gauss random noise.Cross-bispectrum and coherent cross-bispectrum of the higher-order statistics have the advantages of suppressing Gauss and non-Gauss colored noise.Real OBC data seawater depths calculated by the proposed method match very well with measured seawater depths.These inversed seawater depths are used to dual-sensor data summing,and a good suppression of seawater reverberation is achieved,which lays a solid foundation for the subsequent velocity model building and migration.
Barr F J and Sanders J I.Attenuation of water column reverberations using pressure and velocity detectors in a water-bottom cable[C].SEG Technical Program Expanded Abstracts,1989,8:653-656.
[2]
Barr F J.Dual-sensor OBC technology[J].The Lea-ding Edge,1997,16(1):45-51.
[3]
Dragoset B,Barr F J.Ocean-bottom cable dual-sensor scaling[C].SEG Technical Program Expanded Abstracts,1994,13:857-860.
梁鸿贤,秦宁,高丽董.海底电缆双检资料正演模拟及特征分析[J].地球物理学进展,2017,32(4):1798-1802.LIANG Hongxian,QIN Ning,GAO Lidong.Numerical simulation and feature analysis of OBC dual sensor data[J].Progress in Geophysics,2017,32(4):1798-1802.
[8]
赫建伟,邓勇,邓盾,等.基于非高斯性最大化的起伏海面环境下双检信号波场分离[J].石油地球物理勘探,2018,53(4):694-702.HE Jianwei,DENG Yong,DENG Dun,et al.Dual-sensor signal wavefield separation based on non-Gaussianity maximum under undulation sea surface[J].Oil Geophysical Prospecting,2018,53(4):694-702.
[9]
Max D,Ramesh N.OBC multiple suppression with the Texas two-step[C].SEG Technical Program Expanded Abstracts,2005,24:2123-2126.
[10]
Soubaras R.Ocean bottom hydrophone and geophone processing[C].SEG Technical Program Expanded Abstracts,1996,15:24-27.
[11]
Vaughn B,Dennis C.Dual-sensor summation of noisy ocean-bottom data[C].SEG Technical Program Expanded Abstracts,1996,15:28-31.
[12]
王振华,夏庆龙,田立新,等.消除海底电缆双检地震资料中的鸣震干扰[J].石油地球物理勘探,2008,43(6):626-635.WANG Zhenhua,XIA Qinglong,TIAN Lixin,et al.Elimination of singing interference in OBC dual-geophone seismic data[J].Oil Geophysical Prospecting,2008,43(6):626-635.
[13]
张保庆.海底双检地震数据质量品质影响因素分析及关键处理技术研究[D].北京:中国石油大学(北京),2016.ZHANG Baoqing.Quality Influence Factor Analysis of Ocean Bottom Dual-Sensor Seismic Data and Key Processing Technical Research[D].China University of Petroleum (Beijing),Beijing,2016.
[14]
张兴岩.海底四分量地震资料处理方法研究[D].北京:中国矿业大学,2017.ZHANG Xingyan.Research of 4C-OBC Seismic Data Processing Technology[D].China University of Mining & Technology,Beijing,2017.
Backus M M.Water reverberations-their nature and elimination[J].Geophysics,1959,24(2):233-261.
[20]
Paffenholz J,Barr F J.An improved method for deriving water-bottom reflectivities for processing dual-sensor ocean-bottom cable data[C].SEG Technical Program Expanded Abstracts,1995,14:987-990.
[21]
董崇志,宋海斌,王东晓,等.海水物性对地震反射系数的相对贡献[J].地球物理学报,2013,56(6):2123-2132.DONG Chongzhi,SONG Haibin,WANG Dongxiao,et al.Relative contribution of seawater physical property to seismic reflection coefficient[J].Chinese Journal of Geophysics,2013,56(6):2123-2132.
龚旭东,周滨,高梦晗,等.检波点水深误差对OBC双检资料合并处理的影响与对策[J].石油物探,2014,53(3):324-329.GONG Xudong,ZHOU Bin,GAO Menghan,et al.The influence and strategy of water depth error at receivers on dual-sensor summing processing[J].Geophysical Prospecting for Petroleum,2014,53(3):324-329.
[24]
高少武,钱忠平,马玉宁,等.基于延迟波场特征法的海底反射系数估算技术[J].石油物探,2018,57(3):389-394.GAO Shaowu,QIAN Zhongping,MA Yuning,et al.Estimating ocean bottom reflection coefficient using delayed wavefield charactistic method[J].Geophysical Prospecting for Petroleum,2018,57(3):389-394.