实际地层条件下爆炸震源子波模拟研究
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摘要
炸药激发是陆地上地震勘探的主要激发方式。不同的激发位置得到的子波的频率成分、主频、频宽均不同。由于反射系数及虚反射等多方面的影响,子波波形和频谱随着传播的距离而改变,从而影响地震资料的分辨率。通过计算得到了均匀弹性介质中的球腔震源作用下的位移公式,并分析了影响球腔震源子波的各个因素。最后在实际地层中得到了不同位置激发下的震源子波,以及各个激发位置下所得到的子波的频率变化。通过分析远场子波的主频及频宽得到最佳激发位置,来指导实际震源的安置。
Explosive source is a main method in land seismic exploration.The frequency components,dominant frequency,bandwidth of the source wavelet are vastly different with different excitation locations.Because of the reflection coefficient,ghost reflection and other aspects,the waveform and frequency spectrum of the wavelet change as the distance changes,thus affecting the resolution of seismic data.This paper calculated displacement formula in the uniform elastic medium under the action of the ball cavity source and analyzed the impact of the various factors.Finally,the source wavelet was excited in the different locations of the actual formation,and the different excitation locations can make the wavelet frequency components vary.Through the analysis of frequency and bandwidth,the optimal excitation position was got to guide the resettlement of the actual source.
Explosive source is a main method in land seismic exploration.The frequency components,dominant frequency,bandwidth of the source wavelet are vastly different with different excitation locations.Because of the reflection coefficient,ghost reflection and other aspects,the waveform and frequency spectrum of the wavelet change as the distance changes,thus affecting the resolution of seismic data.This paper calculated displacement formula in the uniform elastic medium under the action of the ball cavity source and analyzed the impact of the various factors.Finally,the source wavelet was excited in the different locations of the actual formation,and the different excitation locations can make the wavelet frequency components vary.Through the analysis of frequency and bandwidth,the optimal excitation position was got to guide the resettlement of the actual source.
引文
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[3]Richard D.Miller,Susan E.Pullan,Don W.Steeplesand James A.Hunter.Field comparison of shallow P-wave seismic sources near Hpuston,Texas[J].Ge-ophysics,1994,11:1713~1728.
[4]Andrew L.Kurkjiar.Theoretical far-field radiationfroma low-frequency horizontal acoustic point forcein a vertical borehole[J].Geophysics,1986,51(4):930~939.
[5]张智,刘财,邵志刚.地震勘探中的炸药震源药量理论与实验分析[J].地球物理学进展,2003,12(4):724~728.
[6]何樵登,韩立国.地震波理论[M].长春:吉林大学出版社,2005.38~46.
[7]任义庆.地震爆炸震源模拟[J].石油物探,1993,37(3):15~21.
[8]梁运基,贾烈明等.虚反射与长药柱对地震子波频谱影响规律分析[J].石油天然气学报,2006,28(4):55~57.
[2]国胜兵,潘越峰,高培正,等.爆炸地震波模拟研究[J].2005,7(4):335~340.
[3]Richard D.Miller,Susan E.Pullan,Don W.Steeplesand James A.Hunter.Field comparison of shallow P-wave seismic sources near Hpuston,Texas[J].Ge-ophysics,1994,11:1713~1728.
[4]Andrew L.Kurkjiar.Theoretical far-field radiationfroma low-frequency horizontal acoustic point forcein a vertical borehole[J].Geophysics,1986,51(4):930~939.
[5]张智,刘财,邵志刚.地震勘探中的炸药震源药量理论与实验分析[J].地球物理学进展,2003,12(4):724~728.
[6]何樵登,韩立国.地震波理论[M].长春:吉林大学出版社,2005.38~46.
[7]任义庆.地震爆炸震源模拟[J].石油物探,1993,37(3):15~21.
[8]梁运基,贾烈明等.虚反射与长药柱对地震子波频谱影响规律分析[J].石油天然气学报,2006,28(4):55~57.
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