可控震源动态扫描时距规则定量优化设计及应用

Quantitative optimization design of vibroseis dynamic sweep time-distance rule and its application

可控震源动态扫描地震数据采集过程中,相邻多组震源震动时产生的地震波会相互干涉,从而影响地震数据采集品质。合理设计采集时距规则可以降低可控震源高效采集时震源相互干涉的影响,同时平衡原始数据采集品质和可控震源高效采集施工效率。以往动态扫描时距规则设计时,对资料处理过程中高效采集噪声的压制效果考虑较少,并且时距规则的设计缺乏统一量化标准。首次将高效采集噪声压制效果引入动态扫描时距规则设计中,对现场不同地表类型采集的可控震源相关前记录采用互相关法获取高效采集噪声信息,以环境噪声能量、干涉时空位置和干涉区域能量比值为阈值建立量化统一的时距规则设计标准,形成了可控震源动态扫描时距规则定量优化设计方法。动态扫描时距规则定量优化设计方法优化了现场试验方案,降低了试验工作量,与地震数据处理信噪分离技术相适应优化滑动时间参数,定量与定性相结合设计时距规则避免了以频率扫描为主的常规定性分析方法带来的人为主观歧义。该方法不受勘探区地表特征约束,能够在保障地震数据品质条件下最大限度地提高可控震源采集施工效率,是对可控震源高效采集配套技术的补充和完善,有助于“两宽一高”地震采集技术的推广应用。

In the process of vibroseis dynamic sweep acquisition,the seismic waves generated by adjacent multiple groups of sources interfere with each other,which affects the quality of seismic data.A reasonable design of acquisition time-distance rule can minimize the interference between efficient sources while ensuring the quality of raw data and the efficiency of vibroseis acquisition.In the past,the design of dynamic sweep time-distance rule did not consider the suppression effect of efficient acquisition noise and lacked a quantitative unified standard.This paper introduces the suppression effect of efficient acquisition noise into the design of dynamic sweep time-distance rule for the first time.Based on the uncorrelated data acquired by different surface sources through field tests,the cross-correlation method is used to obtain the efficient acquisition noise data,and a quantitative unified standard for design of time-distance rule is established with the energy of environmental noise,spatiotemporal position of interference,and energy ratio of the interference area as the thresholds.Thus,a method for quantitative optimization design of vibrosesis dynamic sweep time-distance rule is formed.This method can optimize the field test scheme and reduce the testing workload.It is compatible with the signal-noise separation technology in seismic data processing to optimize the slip time parameter.This quantitative and qualitative combined method can avoid the artificial subjective ambiguity brought by the conventional qualitative analysis method based on frequency scanning.Moreover,this method is not constrained by the surface characteristics of the exploration area and can maximize the efficiency of acquisition while ensuring the quality of seismic data.The proposed method for quantitative optimization design of vibrosesis dynamic sweep time-distance rule is an important supplement to the supporting technology of efficient vibroseis acquisition,and facilitates the application of“wide azimuth,broadband,and high-density”seismic acquisition technology.