基于HHT方法的地层Q值补偿方法研究

Research of compensation method for formation Q value based on HHT method

常规的基于叠后地震资料的地层Q值补偿方法受数据平均效应的影响,Q值估算精度较低,导致保真性差,而HHT时频分析可以反映出信号的局部信息,基于以上原因,提出一种基于HHT方法的地层Q值补偿方法。首先应用HHT分频技术将浅层、中深层地震数据分成不同的频率范围,得到不同目标层频率尺度的地震数据;然后在HHT时频域内通过谱比法提取Q值;最后分别进行地层Q值振幅补偿和相位补偿。该方法针对不同的目标地层将地震数据分解成不同的频率尺度,避免了不同频率成分之间的干扰,而且可针对性处理目标层的频率信息,提高了地层Q值提取的稳定性。模型试算和实际资料应用表明,该方法能够有效地对振幅和相位进行补偿,使中深层反射波形得到恢复,主频提高,频带展宽,地震资料的品质得到提升。

The conventional Q-value compensation method based on post-stack seismic data is affected by the data average effect,and the estimation accuracy of Q value is always low that results in poor fidelity.Fortunately,the HHT time-frequency analysis may reflect the local information of the signal.Therefore,this paper proposed a formation Q-value compensation method based on HHT.First,using the HHT spectral decomposition technology to divide the shallow,medium and deep seismic data into different frequency ranges,and the seismic data for different target layer frequency scales are acquired.Then,the Q value is extracted with spectral ratio method from the HHT time-frequency domain,and finally,the formation Q amplitude compensation and phase compensation are respectively realized.The method may decompose seismic data into different frequency scales for different target strata,avoid interference between different frequency information components,effectively deal with the frequency information of the target layer,and improve the stability of formation Q value extraction.Trial model calculation and practical data application demonstrate that the method can effectively compensate the amplitude and phase,restore the mid-deep reflection waveform,improve the main frequency,widen the frequency band,and improve the quality of seismic data.