CDP道集内的AVO效应及对岩性处理的影响

AVO Effects in CDP Gathers and its Influences to Lithologic Processing

华北石油局第三普查勘探大队,咸阳712000

The Third Reconnaissance Party, Huabei Petroleum Bureau, Xianyang 712000

传统的水平叠加理论认为CDP道集内的共反射点地震道振幅经时间校正 (动校正)后是法线入射反射的结果,而忽略了由偏移距 (入射角)的变化而带来的振幅变化 (AVO)效应,使下一步的保幅叠加和岩性处理出现“假象”。本文通过鄂尔多斯盆地和塔里木盆地两种类型碎屑岩地质地球物理模型的AVO正演分析和叠加剖面反演处理的比较,指出了它对保幅和岩性处理的影响和改造作用,提出了避免这些影响的基本设想。

Time corrected(DMO) seismic amplitudes of common reflection points are thought to be resulted from reflections in normal direction in conventional horizontal stacking theory, thus amplitude variations versus offsets(AVO) are omitted which will give rise to artifacts in further processing such as amplitude restoration and lithologic processing. By AVO forward analysis and comparison between inverted stack sections on geologic and geophysical models for clastic rock from Erdos and Tarim basins, this paper discloses its affects to amplitude and lithologic processing and provides some ways to avoid these negative influences.