沙漠区宽频高能噪声对地震记录的影响
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摘要
在沙特阿拉伯沙漠地区地震勘探采集中主要采用可控震源作为激发震源,在单炮记录的频谱中,可发现一些呈线性分布的高能宽频噪声,在频谱图上表现为亮条,在各个单炮记录之间随机出现,但在连续两张单炮记录的同一道上很少同时出现。本文通过对地震记录上的高能宽频噪声进行研究后认为:①高能宽频噪声频率随时间呈线性衰减变化,记录初始阶段起始频率一般为30～60Hz,终了频率为10～40Hz,起始频率和终了频率差约为20Hz,与记录长度时间内参考信号的频率变化差相同;②脉冲的能量级为102,噪声的能量级为10-3;③噪声产生的时间基本集中在14时至22时之间,发生噪声的位置集中在沙丘起伏地区的迎风坡和坡底;④高能宽频噪声是由静电释放瞬间产生的干扰形成的。文中还提出了一些防范措施来尽量避免高能宽频噪声对生产的影响。
The vibroseis is mainly used for shooting source of seismic data acquisition in desert area of Saudi Arabia.The broad-frequency and high-energy noise with linear distribution is discovered in the frequency spectrum of single shot record [1],appeared as the bright strip in spectrum and random showed in single shot record,and is rarely found on same channel of successive two single shot records.After studying the broad-frequency and high-energy noise on seismic records,the paper considered that ①the frequency of broad-frequency and high-energy noise attenuated linearly with time:initial frequency of records is generally 30~60Hz and final frequency is 10~40Hz,and the difference between the initial and final frequency is about 20Hz,same as the difference of frequency variation in reference signal during the recording length time;②the energy level of pulse is 102 and of noise is 10-3;③the time producing noise is basically from 14h to 22h,and places producing noise are up-wind slop and bottom of slop in fluctuant area of sand dune;④the broad-frequency and high-energy noise is formed by interference produced by electrostatic discharge in a twinkling.The paper also presented some measures to avoid the influence of the broad-frequency and high-energy noise on production as far as possible.
The vibroseis is mainly used for shooting source of seismic data acquisition in desert area of Saudi Arabia.The broad-frequency and high-energy noise with linear distribution is discovered in the frequency spectrum of single shot record [1],appeared as the bright strip in spectrum and random showed in single shot record,and is rarely found on same channel of successive two single shot records.After studying the broad-frequency and high-energy noise on seismic records,the paper considered that ①the frequency of broad-frequency and high-energy noise attenuated linearly with time:initial frequency of records is generally 30~60Hz and final frequency is 10~40Hz,and the difference between the initial and final frequency is about 20Hz,same as the difference of frequency variation in reference signal during the recording length time;②the energy level of pulse is 102 and of noise is 10-3;③the time producing noise is basically from 14h to 22h,and places producing noise are up-wind slop and bottom of slop in fluctuant area of sand dune;④the broad-frequency and high-energy noise is formed by interference produced by electrostatic discharge in a twinkling.The paper also presented some measures to avoid the influence of the broad-frequency and high-energy noise on production as far as possible.
引文
[1]陆基孟.地震勘探原理.山东东营:石油大学出版社,1993
[2]熊翥.地震数据数字应用技术.北京:石油工业出版社,1993
[3]王旺志等.可控震源在城区勘探中的应用与效果.石油物探,2003,42(增刊):118～120
[4]王民等.可控震源资料处理方法研究.石油物探,2003,42(增刊):188～191
[2]熊翥.地震数据数字应用技术.北京:石油工业出版社,1993
[3]王旺志等.可控震源在城区勘探中的应用与效果.石油物探,2003,42(增刊):118～120
[4]王民等.可控震源资料处理方法研究.石油物探,2003,42(增刊):188～191
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