西部大沙漠区近地表地震波衰减及高频补偿技术研究
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摘要
大沙漠区近地表巨厚沙层是导致地震波高频成分严重衰减、地震分辨率降低的根本原因。针对这一问题,采用常规微测井方法进行高频补偿,往往难以奏效。为此,本文利用大炮震源微测井数据,分析了大沙漠区近地表地震波的衰减规律,采用近地表高频补偿方法,较好地补偿了近地表巨厚沙层对地震波的吸收和衰减,克服了常规微测井数据的不足。补偿后的地震数据的优势信噪比频带宽度较补偿前明显拓宽,东河砂岩尖灭点更加清晰,提高了岩性勘探的分辨率。
Near-surface giant-thickness of sand layer in large desert area is a basic reason seriously attenuating high components of seismic waves and reducing seismic resolution. Facing this issue, using ordinary uphole survey approach to carry out the high-frequency compensation is often difficult to be successful. For that reason, using uphole survey data of production shots, the paper analyzed attenuation law of near-surface seismic waves in large desert area and adopted near-surface high-frequency compensation approach, which better compensated the absorption and attenuation of seismic waves by near-surface giant-thickness of sand layer and overcame the shortage of ordinary uphole survey data. The bandwidths of high S/N ratio in seismic data have been greatly broadened after compensation by comparison with that before compensation. The pinchout point of Donghe sandstone is more distinctive, improving the resolution of lithologic exploration.
Near-surface giant-thickness of sand layer in large desert area is a basic reason seriously attenuating high components of seismic waves and reducing seismic resolution. Facing this issue, using ordinary uphole survey approach to carry out the high-frequency compensation is often difficult to be successful. For that reason, using uphole survey data of production shots, the paper analyzed attenuation law of near-surface seismic waves in large desert area and adopted near-surface high-frequency compensation approach, which better compensated the absorption and attenuation of seismic waves by near-surface giant-thickness of sand layer and overcame the shortage of ordinary uphole survey data. The bandwidths of high S/N ratio in seismic data have been greatly broadened after compensation by comparison with that before compensation. The pinchout point of Donghe sandstone is more distinctive, improving the resolution of lithologic exploration.
引文
[1]Shi Zhanjie,Tian Gang,Dong Shixue et al.Attenua-tion compensation of low-velocity layers using micro-seismogramlogs:case studies.Journal of Geophysics and Engineering,2004,1(3):181～186
[2]Tian Gang,Shi Zhanjie et al.Geophone coupling match and attenuation compensation in near-seismic exploration.Journal of Environmental and Engineering Geophysics,2006,11(2):111～122
[3]田钢,石战结等.利用微测井资料补偿地震数据的高频技术研究.石油地球物理勘探,2005,40(5):546～549
[4]Yil maz.Seismic Data Analysis.Published by Society of Exploration Geophysicists,2001,Second Edition,Vol-ume I:255～258
[2]Tian Gang,Shi Zhanjie et al.Geophone coupling match and attenuation compensation in near-seismic exploration.Journal of Environmental and Engineering Geophysics,2006,11(2):111～122
[3]田钢,石战结等.利用微测井资料补偿地震数据的高频技术研究.石油地球物理勘探,2005,40(5):546～549
[4]Yil maz.Seismic Data Analysis.Published by Society of Exploration Geophysicists,2001,Second Edition,Vol-ume I:255～258
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