垂直地震剖面上下行波分离技术

ON SEPARATION TECHNIQUE OF VSP UPWARD AND DOWNWARD TRAVELLING COMPONENTS

地质矿产部石油物探研究所

垂直地震剖面(VSP)技术的生命力体现在其丰富的波场信息、较高的分辨率和信噪比。而高保真地分离VSP波场,以充分反映出精细的波场特征,则是VSP资料处理中的重要环节之一。本文介绍了垂直地震剖面处理中几种上行波与下行波分离技术:最佳多道速度滤波是F—K速度滤波方法中较好的技术之一,如何选择合适的参数则是其关键所在;在实际工作中提出的叠加消去法简捷而又富有成效;新的中值滤波技术与叠加消去法效果相当,又各有特点。文中侧重讨论了它们的应用效果。

The vitality of VSP lies in possessing a wealth of wave field information as well as its high resolution and desired signal-to-noise ratio. What’s more, one of the key links dealing with VSP data processing is to separate VSP wave field in high fidelity so that it can fully reflect the detailed and distinctive features of the wave field.As to how to deal with several VSP upward and downward travelling components using separation technique is described in this paper. The optimum multichannel velocity filtering is assessed as one of the generally accepted approaches in F-K velocity filtering. It seems certain that the crux of the matter is how to pick up the appropriate parameters. From routine practice it tells the "stacking elimination" method is very accessible and proved to be remarkably successful most of the time. The newly adopted "median filtering" technique and "stacking elimination" technique are producing about the same effect but each has its own uniqueness in term of characteristics. Moreover, their practicability is in particular remarked in the paper.