等效偏移距在垂直地震剖面中的研究及应用

The study and application of equivalent offset migration of VSP

基于散射理论的等效偏移距方法在地震资料数据处理中具有独特的优势,尤其在速度分析和偏移成像方面。笔者将该理论应用到垂直地震剖面(VSP)数据处理中,研究了基于该理论的VSP数据共散射点道集的形成方法,并试验了VSP共散射点道集在速度分析和成像方面的应用效果。理论模型和实际资料测试结果表明,该方法能方便有效地为VSP提供不受初始速度和地层倾角影响的有效偏移速度,除了能在常规成像方法的成像区域内准确成像外,还能在常规成像方法的盲区外有效成像,在一定程度上扩大了VSP方法的成像范围,具有有较好的研究意义和应用前景。

The concept of equivalent offset migration (EOM) method is introduced to vertical seismic profile (VSP) in the paper.The definition of the VSP equivalent offset migration and data processing method based on VSP equivalent offset migration method are also introduced.The EOM method,which has particular advantages in velocity analysis and imaging,provides ideas for VSP scattered wave imaging and velocity analysis.The results of theoretic test and analysis of real data show that the VSP equivalent offset migration method is effective and feasible, and has the prospect of study and application.