非稳态地震记录时变子波估计

Time-varying seismic wavelet estimation from nonstationary seismic data

地震子波估计是地震资料处理和解释中的一个关键问题,子波估计的可靠性会直接影响反褶积和反演的准确度.现有的子波估计方法分为确定型和统计型两种类型,本文通过结合这两类方法,利用确定型的谱分析法和统计型的偏度最大化方法,分别提取时变子波的振幅和相位信息,得到估计的时变子波.这种方法不需要对子波进行任何时不变或相位等的假设,具有对时变相位的估计能力.进而利用估计时变子波进行非稳态反褶积,提高地震记录的保真度,为精细储层预测和描述提供高质量的剖面.理论模型试算验证了方法的可行性,通过实际地震资料的处理应用,表明该方法能有效地提取出子波时变信息.

Seismic wavelet estimation is an important part of seismic data processing and interpretation, whose reliability is directly related to the accuracy of deconvolution and inversion. The methods for seismic wavelet estimation can be classified into two basic types, deterministic and statistical. By combining the two types of the methods, using the spectral coherence method in the deterministic method and the skewness attribute method in the statistical method, the amplitude and phase of the time-varying wavelets are estimated separately. There is no assumption on the wavelet＇s time-independent nature or the phase characteristic. The advantage of this method is the ability to estimate time-varying phase. Phase-only corrections can then be applied by means of a time-varying phase rotation. Alternatively, amplitude and phase deconvolution can be achieved to enhance the resolution and support the fine reservoir prediction and description. We test this method on both synthetic and real data examples. Synthetic examples prove its feasibility while the real data example demonstrates its ability to estimate the time-varying characteristics of wavelets.