基于频率域小波的地震信号多子波分解及重构

Seismic signal multi-wavelet decomposition and reconfiguration based on wavelet in frequency domain

多子波分解是将一个地震道分解为不同频率的子波集,并针对不同的目标地质异常体,选择不同频率的单一地震子波或子波段,重构新的地震剖面和数据体,以便进行更精准的地质地球物理解释和储层特性描述。文中根据频率域小波的解析表达式及小波变换时间—尺度域和时间—频率域的转化关系,提出一种能适应多子波分解精度要求的处理方法。对合成地震信号及含气裂缝模型正演剖面的多子波分解与重构处理表明,该方法具有较高的精度,处理结果能直接用于含油气特征的检测;对实际地震数据处理得到的单频剖面也可明显地表征含油气储层的特征信息。

Multi-wavelet Decomposition is a method that decomposes seismic trace into wavelet sets with different frequencies,and for different geological anomalies a single seismic wavelet or wavelet band with different frequencies can be selected to reconfigure new seismic section and data set so that the geological and geophysical interpretation and reservoir characteristic description can be accurately conducted. According to the analytical expression of wavelet in frequency domain and the converting relationship of wavelet transform in time-scale domain and time-frequency domain,a processing method which can meet the accuracy requirement of the multi-wavelet decomposition is developed. Through multi-wavelet decomposition and reconfiguration processing for the synthetic seismic signal and gas-bearing fracture model forward section,it is proved that the method has a high precision,and the processing results can be directly used in detecting the hydrocarbon-bearing characteristics,and the single frequency sections obtained from the real data processing results can obviously characterize the information of the hydrocarbon-bearing reservoirs.