双平方根算子波场延拓道集速度分析

Velocity analysis on wavefiled continued gathers from double squared root operator

1. 中国石油辽河油田分公司勘探开发研究院计算所,辽宁盘锦124010;2. 中国科学院计算数学与科学工程计算研究所数学与系统科学研究,北京100080;2. 杭州石油地质研究所,浙江杭州310023

Exploration & Development Research Institute of CNPC Liaohe Oilfield Corporation, Panjin 124010, China

在中心点半偏移距域, 利用波动方程的叠前双平方根算子, 实现炮点及检波点波场向下延拓。通过速度扫描, 在波场延拓后的深度域共中心点道集和经分选后的共成像点道集上, 分析速度变化对成像点道集的影响。利用分偏移距成像, 修正速度场, 以达到提高成像精度的目的。

In the domain of common middle point (CMP) and half-offset,the wavefields at sources and receivers are continued downwards using prestack double square root operators of wave equation. The influences of velocity variance on imaging point gathers are analyzed by velocity scanning in CMP gathers and sorted common receiver gathers in depth after wave field continuation. We update the velocity field by separated offset imaging to raise imaging precision.