垦71井区三维VSP资料波场分离方法应用研究

Research on wave Held separation method of 3-D VSP data in Ken 71 well area

三维VSP资料是多偏移距VSP资料,资料中多种类型的波叠合在一起形成复杂波场。从复杂波场中分离出单一的保幅反射波波场是三维VSP波场分离的重要工作。常规二维VSP波场处理方法单一,难以适用于复杂的三维波场处理。针对三维VSP资料的波场特点,以分离上行反射P波为例,将单一波场分离方法加以适当组合,对垦71井区三维VSP实际资料进行了应用研究。结果表明,波场分离处理中叠加消去法和中值滤波相结合以及F-K滤波和中值滤波相结合的方法克服了单一方法的缺陷,波场处理后获得了波组特征明显、波场清晰单一的上行反射P波保幅波场,取得了较好的波场分离效果。

3-D VSP data are multi-offset data. Many kinds of waves stack together to form the complicated wave field. So the aim of 3-D VSP wave field separation is separating a single reflection pre-served-amplitude wave field from the complicated wave field The conventional 2-D VSP wave field processing method is so simple that it is difficult to adapt to 3-D VSP wave field. According to the characteristics of 3-D VSP data and taking upgoing P-wave separation as an example, single wave field separation method is used in combination and applied to actual data. The result shows that, in separating a wave field, the combination of stack elimination method with the median filtering method and the combination of F-K filtering method with the median filtering method can overcome the shortcoming of only using a single method, making the upgoing P-wave an obvious characteristic in wave group and the wave field a single one. Both of the two methods are suitable for 3-D VSP wave field separation processing in this area.