【摘要】 叠前深度偏移速度分析是地震数据处理方法研究的重点,是影响地震成像效果的关键技术之一。本文的基于角度域共成像点道集剩余曲率的偏移速度分析方法,旨在通过角度域共成像点道集(ADCIGs)来建立局部入射角与偏移深度之间的联系,通过角度道集剩余速度分析来修正、更新偏移速度。不同于偏移距域共成像点道集(ODCIGs),ADCIGs较少地受到由于多路径问题而产生的波场干涉假象的影响,更适合于偏移速度分析。本文在推导出基于ADCIGs的水平地层深度剩余量公式的基础上,提出了基于ADCIGs的沿层扫描法速度更新流程,凹陷模型和实际资料的试处理表明了本方法的正确性和有效性。更多还原

【Abstract】 Pre-stack depth migration velocity analysis is one of the keys to influencing the imaging quality of pre-stack migration.In this paper we cover a residual curvature velocity analysis method on angle-domain common image gathers(ADCIGs) which can depict the relationship between incident angle and migration depth at imaging points and update the migration velocity.Differing from offset-domain common image gathers(ODCIGs),ADCIGs are not disturbed by the multi-path problem which contributes to imaging artifacts,thus influencing the velocity analysis.On the basis of horizontal layers,we derive the residual depth equation and also propose a velocity analysis workflow for velocity scanning.The tests to synthetic and field data prove the velocity analysis methods adopted in this paper are robust and valid.更多还原