复杂构造对下伏地层地震波动力学特征的影响

复杂构造下伏地层的CRP(共反射点)射线路径和振幅变化特征,对后续地震资料的研究如叠前反演、AVO(振幅-炮检距关系)特性分析至关重要。采用射线追踪法进行地震正演模拟,将过邻近井地震偏移剖面解释成果应用于复杂构造模型的设计,对复杂构造下伏地层地震波运动学和动力学特征的影响程度进行分析。分析表明,常规的复杂构造勘探方法所获得的CRP道集,其地表接收点关于CRP非对称性严重,陡坡带底界面上共反射点覆盖次数和反射能量横向变化不均匀性严重,仅在局部地段达到满覆盖次数,复杂构造对下伏地层反射动力学特征影响较大。

Impact of Complex Structures on Seismic Wave Dynamics Characteristics in Underlying Strata

The CRP ray path and amplitude variation characters in underlying strata of complex structure are of significance to the study of continuous seismic information such as the pre-stack inversion and AVO character analysis. In this paper, the ray tracing method is used for the seismic forward modeling, and the neighborhood well migration data are applied for the model design of complex structure. The analysis of the effect of the complex structure on underlying strata's seismic wave dynamics characteristics shows that the CRP from conventional methods for complex structural exploration has an asymmetric property, including CRP from actic region bottom boundary and the lateral reflection energy variation. It is shown that only local zones can reach full seismic coverage, which posts that complex structure has a big impact on underlying zone's reflecting dynamics characters.