深度-射线域偏移速度分析

Migration velocity analysis in depth-ray domaia

中国石化石油勘探开发研究院南京石油物探研究所,江苏南京 210014

Institute of Geophysical Prospecting, SINOPEC Research Institute of Petroleum Exploration and Development, Nanjing 210014, China

根据波场外推理论和共角度成像条件,给出了基于深度-射线域共成像道集的偏移速度分析方法。该方法采用速度扫描技术,以共成像点道集同相轴拉平,即成像质量最优为准则提取速度修正量,可以采取沿构造层位或道集深度2种方式进行交互式速度分析。用Marmousi模型对该速度分析方法进行了沿深度方向和沿层位的偏移速度分析测验,结果表明,用该方法提取的速度修正量与预设的偏移速度误差几乎一致。

Velocity model updating is key in the iteration flow of prestack depth migration modeling. Model updating is depended on migration velocity analysis.It is present that the method on migration velocity analysis with depth-ray parameter CIGs (Common Image Gather) based on wave field extrapolation theory and common angle image condition. The method is flattening CIGs event (i.e.the image quality is the best) using to velocity scan technology, is extracting velocity update. The interactive velocity analysis is along with structure stratum or gathers depth.It is test to migration velocity analysis on two modes as Marmousi model data.The result shows that extracting velocity update on this method is almost consistent with migration analysis beforehand.