【摘要】 研究并分析了地震波叠前逆时偏移技术对地面地震、井中地震及井间地震这3种地震观测方式采集的数据进行偏移成像的适用性。以含不同倾角的速度模型和Marmousi速度模型为例,合成了对应观测方式的若干共炮点道集,并进行了逆时偏移数值实验。结果表明:逆时偏移方法适用于这3种地震观测方式,且均能获得较好的成像效果,通过低频噪声压制处理可进一步提高信噪比。其中,地面地震观测方式须对直达波和折射波波场进行精细切除,井中地震和井间地震观测方式则须保留初至波波场(下行直达波),才能不破坏反射和透射这种波场之间的能量转换关系,并最大程度地刻画地质构造的细节特征。更多还原

【Abstract】 This paper analyzed the applicability of the seismic wave pre-stack reverse-time migration technology on the migration of data from different seismic observation models,such as surface seismic,borehole seismic and crosswell seismic.Taking velocity model with different dip angle and Marmousi velocity model as examples,we synthesized several common shot gathers corresponding to observation models,and carried out numerical experiments on reverse-time migration further.The results show that the reverse-time migration method is suitable for these seismic observation models,and can get perfect imaging results;the S/N ratio can be further improved by low-frequency noise suppression method.The direct wave and refracted wave of the surface seismic observation model must be finely cut,and the first-arrival wave field(down propagating direct wave) must be preserved of the borehole seismic and crosswell seismic observation model.In this way,the wave field energy transformation relation between the reflection and transmission can be remained unchanged,and it can depict detailed features the geological structure to a maximum extent.更多还原