基于最小偏移距初至切除线监控炮点偏移新方法

New Methods for Monitoring Shot-points Offsets Based on the First Arrival Muting Line of the Minimum Offset

复杂地表往往使地震采集过程中控制炮点偏移的难度加大,面对地形复杂、近地表速度横向剧烈变化的黄土塬区,问题尤为突出。面对此类复杂探区,使用常规的线性动校方法监控炮点偏移无论是效果,还是效率都不太理想,找到一种有效的炮偏监控方法对于野外地震资料采集质量的提高至关重要。为此,本文介绍一种基于分选最小偏移距初至切除线来监控炮点偏移的方法,该方法对复杂地表结构效果尤为显著。使用该方法首先根据估算出的工区可能最大偏移量来抽取适当数量的近接收线和道记录,在处理系统交互状态下,对比抽取记录的实际炮点位置与基于最小偏移距初至切除线显示的理论炮点位置来确定偏移量的大小。实际应用效果表明,该方法可以精确地检测炮点沿偏(沿接收线方向的偏移)和垂偏(垂直接收线方向的偏移)距离,有效提高野外地震资料采集的质量。

Complex surface is often difficult to control shot--points offsets in a process of seismic acquisition. Faced with the complex terrain and the dramatic changes of near sur- per, it describes a method for monitoring shot--points offsets based on the first arrival mu- ting line of the minimum offset. In the interaction state of the processing system, several channels are extracted according to estimated maximum offset of the area. The size of the offset is determined through the first arrival of shot records and the muting line. Practical application shows that the method can accurately check shot--points offsets along the re-ceiving line and in vertical direction of receiving line, which improves the quality of field seismic data acquisition.