地震数据炮域规则化方法研究及应用  

Research on the regularization method for seismic data in shot domain

作　　者：许璐[1] XU Lu(SINOPEC Geophysical Research Institute,Nanjing 211103,China)

机构地区：[1]中国石油化工股份有限公司石油物探技术研究院,江苏南京211103

出　　处：《物探与化探》2018年第6期1245-1252,共8页Geophysical and Geochemical Exploration

基　　金：国家科技重大专项(2017YFB0202904)

摘　　要：叠前深度逆时偏移成像技术是目前处理复杂高陡构造成像的有效方法之一,作为一种高精度的炮域波动方程偏移方法,需要规则采集的高质量炮集数据作为输入。受复杂地质条件的限制,实际采集到的地震数据在空间方向往往是稀疏不规则采样的,存在严重的空间假频和噪声干扰,不满足炮域偏移算法对数据的要求。为了提高逆时偏移成像精度,笔者开展了叠前地震数据炮域规则化方法研究,依据偏移距和方位角将炮集数据分选为OVT(offset vector tile)道集,在OVT域进行地震数据全波数带的迭代加权反假频插值,再基于几何观测系统中炮检点坐标映射关系,从OVT域插值结果中提取规则化后的炮集数据并应用于逆时偏移成像。实际资料的应用结果表明对地震数据进行叠前炮域规则化处理可以有效提高逆时偏移的成像精度。Reverse time migration based on two-way wave equation is an effective method to deal with steeply dipping structures and complicated velocity models.As a method of wave equation migration,the data required to be input are regularly sampled shot gathers.However,the field acquisition is limited by complex geological conditions and the actual seismic data are usually irregularly and sparsely sampled along the spatial direction,and there is a serious spatial aliasing phenomenon,which affects the accuracy of migration.In this paper,the prestack seismic data regularization technique is proposed for reverse time migration,which is based on the correlation of data in the OVT(Offset Vector Tile)domain to realize the iterative anti-aliasing interpolation for the full wave number band of data.It has the advantages of spectral anti-leakage,anti-aliasing and anti-noise.By mapping the coordinates of the shot gathers from the geometric system,the regularized shot gathers are obtained from OVT domain interpolation results,and applied to the reverse time migration.The application results of real data show that the technology can effectively improve the precision of reverse time migration while saving the cost of acquisition.

关 键 词：OVT域 规则化 反频谱泄漏 反假频 逆时偏移 

分 类 号：P631.4[天文地球—地质矿产勘探]