VSP波场研究与应用现状

垂直地震剖面法(VSP)通常采用三分量(3C)检波器记录地震波场信息,而纵、横波震源的应用使其波场进一步丰富和复杂化,开展VSP各种波场特征的研究具有重要的理论和实际应用价值。首先对VSP记录的波场特征进行分析,进而讨论了不同类型震源和不同介质模型的复杂波场分离方法,包括光纤观测VSP波场的噪声特点及压制方法,井筒波与电缆波的产生机理、压制及应用方法,绕射波与断面波的特征及其应用方法,多次波的特征及其压制和应用方法,折射波与导波的传播特征及其应用方法等,重点研究了上行横波和转换波的传播特征、波场分离与矢量合成及多波信息的综合应用方法等。最后,对多分量VSP波场处理中存在的问题进行了分析并对多波应用的前景进行了展望,认为拓展VSP记录中波场传播特征的研究有益于揭示地下复杂构造与地层物性信息,VSP多波解释与反演研究、多波属性的提取与应用有助于油气储层的勘探与开发等,预期VSP多种波场的研究将具有持续攻关和推广应用价值。

Research and application status of VSP wavefields

The vertical seismic profile(VSP)method typically utilizes three-component(3C)geophones to record seismic wavefields;this application of sources of vertical and horizontal wave further enriches and makes the wavefields complex.It is important to understand the various VSP wavefield characteristics owing to their theoretical and practical significance.In this study,the wavefield characteristics of VSP data were analyzed followed by the discussion of different types of sources and separation methods for complex wavefields of various velocity models.This included the fiber-optic observation VSP wavefield,wellbore waves and cable waves,diffraction waves and fault-section waves,multiple waves,refracted and guided waves.Additionally,the propagation characteristics of upward shear and converted waves,wavefield separation and vector rotation,and comprehensive application methods were also discussed.The challenges associated with multi-component VSP wavefield processing were analyzed,with subsequent prospecting of multi-wave applications.Investigating the characteristics of wavefield propagation in VSP records will aid in better understanding underground complex structures and the physical properties of the stratum.The VSP multi-wave interpretation and inversion and multi-wave attribute extraction and application are beneficial for oil and gas exploration and reservoir development of these resources.It is expected that the research on the multiple wavefields of VSP will continue to progress and its outcomes will be widely applied.