单程波法地震波衰减特征数值模拟分析

NUMERICAL SIMULATION ANALYSIS OF THE CHARACTERISTIC OF SEISMIC WAVE ATTENUATION BASED ON ONE-WAY WAVE EQUATION

在非均匀粘弹性介质中,地震波衰减研究能够有效揭示地层吸收特性对地震波的影响。这里从单程波方程出发,结合粘弹性介质中的复波数理论,考虑介质的横向变化,采用分步傅立叶波场延拓技术,推导出适用于横向变速介质的带Q地震记录计算公式,最后将此方法应用于四个不同含Q地层模型。试验表明:单程波法计算速度快,波场信息简单清晰,易于深入分析和反演算法的建立。并且,Q值对地震波波形、能量、频率等都产生了较为明显的影响,对实际资料能量补偿、地震资料分辨率的提高,以及利用衰减特征进行储层识别有一定指导价值。

The seismic wave attenuation study in non-uniform viscoelastic medium could reveal how absorption influences the characteristics of seismic waves.Based on the one-way wave equation,combining with viscoelastic media complex wave number theory,considering lateral variation and using split-step Fourier wave field continuation techniques,a seismic records formula concluding Q has been established which is suitable for the horizontal transmission medium.This method has been applied to four different Q-bearing models.The result shows: one-way wave equation has fast computed-speed,clear and simple wave field which is easy to analysis and establish the inversion algorithm;Q value effects the seismic waveform,energy,frequency and so on,which benefit the further research such as seismic energy compensation,improvement of seismic resolution,concealed reservoir discrimination.