关键词: 能量衰减梯度, 时频分析, 伪Margenau-Hill 分布, 储层预测

Abstract:

Low frequency noise is the main problem of the pre-stack reverse-time migration section. The figure noise removal mechanism based on Laplacian operator and the raising mechanism of the pre-stack reverse-time migration are analyzed. Laplacian operators are used to carry out the pre-stack reverse-time noise suppressing experiments in stacking image domain, common imaging domain and common shot domain respectively, and the results are compared with highpass filter method. The numerical simulation results show that the low-frequency reverse-time migration noise is mainly caused by the inaccuracy of migration velocity, and other reasons of low-frequency reverse-time migration noise are the inconsistency of wavelet form between numerical simulating wavelet and numerical records and the application of the correlation type reverse-time imaging condition. The noise suppressing effects based on the Laplacian operator in the above different domains are obvious, and the result in common shot domain is the best. The above methods in three domains are better than that of the conventional high-pass filter method, the formation detail characteristics of the processed section are clearer, and the horizontal cophasal axes of the common imaging gather are correctly depicted.

Key words: energy attenuation gradient, time-frequencyanalysis, Pseudo-Margenau-Hill distribution, reservoir prediction