井震深度差约束条件下的TTI介质速度建模方法

提出了一种TTI介质中井震深度差约束条件下的速度建模方法。针对空间中测井位置分布的稀疏性,通过引入一个所谓的“桥”函数,根据已知的地质构造将井位处地层的井震深度差信息延拓到整个模型区域,并将此拓展信息作为层析成像反演的约束条件。该方法降低了TTI模型反演参数之间的不确定性,改善了反演算子的病态性,提高了层析成像反演的稳健性。SEAM人工模拟数据和墨西哥湾实际广角地震数据测试结果表明,井震深度差约束条件下的TTI介质速度建模方法的反演结果提高了深度偏移后地层定位精度,改善了共成像点道集中同相轴的拉平程度。

A TTI velocity model building approach is proposed that utilizes well mis-tie information as inversion constraints.Since the well mis-tie information is available only at sparse locations,we introduce a function to bridge the well constraints from sparse locations to their surroundings.This function is consistent with the local geological structures.The inversion scheme could help mitigate the ambiguity between the inverted TTI model parameters and the ill-conditioning of the inversion operator,and improve the robustness of the solution.Tests on SEAM synthetic data and wide-angle field data from the Gulf of Mexico showed that the proposed method can improve the positioning of depth migration image and enhanced the flatness of events in common image gathers.