最小二乘偏移成像方法及应用

Least squares migration imaging method and its application

基于反演理论的最小二乘偏移可为岩性储层估计提供更加保真的、高分辨率反射系数成像,成为当前成像方法的研究热点和发展趋势.研究讨论了实现过程中关键技术环节,包括有限差分解微分方程进行反偏移数据重构,基于数据残差逆时偏移求取梯度及共轭梯度法反演优化算法,并重点研究了最小二乘偏移用于实际处理时的数据残差求取方法,包括面向最小二乘偏移技术的观测数据预处理及能量一致性数据残差求取,探索建立了面向实际资料的最小二乘逆时偏移实现流程,模型和实际资料试处理说明了此方法技术的适用性和有效性.

Compared with the conventional migration method,least squares migration imaging is based on inversion theory,to provide high resolution imaging with more fidelity,for lithologic reservoir estimation. The paper discussed the key technology of LSRTM realization, including data forward modeling based on finite difference method solving differential equations, data residual inverse time migration to obtain gradient and conjugate gradient inversion optimization algorithm,then the paper focused on critical detail processing for real data processing,including observation data preprocessing for lsm technology and energy consistent data residuals,to establish least squares inverse migration technology realization process for real data. Model and real data tests shows the applicability and effectiveness of this method.