论文详情
近年来, 海底节点(OBN)同步震源高效采集方法的研究成为地震勘探领域的热点之一。陆地可控震源数据分离激发参数的选择有时间延迟、相位、扫描长度等3种编码方式。但是, 由于海上空气枪激发的特点, 相位和扫描长度编码适用性差。只能采用时间延迟编码方式。海上混叠采集时间延迟序列的编码是影响数据分离效果的最关键因素之一。提出了一种基于正态分布约束的均匀随机时间分布定量编码准则, 通过目标函数约束构建最优时间序列, 并对比分析了实际自然随机激发时间和其它2种理论模拟的随机时间分布方式在共检波点域的分布特征。利用频率-波数-波数(FKK)域迭代反演方法进行混叠数据分离, 单炮模拟测试结果表明, 构建的最优时间序列比其它3种分布方式更能有效地分离混叠地震数据。海上三维工区高效混叠采集试验结果表明, 根据最优准则构建的延迟时间序列, 能够取得较好的数据分离效果。该研究结果为后续野外混叠采集的延迟激发时间设计提供了技术支持。
Sim-source OBN acquisition is a hot spot in seismic exploration. There are three coding methods: time delay, phase, and scan length, for land vibrator data. Offshore seismic exploration uses air guns, and thus only time delay coding is feasible. The point is how to encode time delay series for de-blending. We propose a quantitative coding criterion for uniform random time distribution based on normal distribution constraints. The optimal time series is constructed using target function constraints, and the features of other three random time distributions are investigated in common detector gathers. Iterative inversion in the FKK domain is performed for de-blending, and single-shot tests show better performance of optimal time series than of other three distributions. A 3D offshore survey shows good results of data separation using the time delay series constructed based on the optimal criterion. Research results offer technical support to source parameter optimization in OBN acquisition.