频率域高分辨率地震波阻抗直接反演方法研究

联合基于压缩感知的稀疏脉冲反射系数谱反演方法(CSSRI法)和常规频率域波阻抗直接反演方法(FIDI法)提出了一种频率域高分辨率地震波阻抗直接反演方法(FIHDI法)。该方法不仅继承了CSSRI法拓宽地震频带宽度的高分辨率性能,同时也保留了常规频率域波阻抗直接反演法的可靠性、稳定性和计算简洁性。理论模型试验结果表明,频率域高分辨率地震波阻抗直接反演法能够精细刻画具有薄层结构的复杂礁滩模型的地层叠置关系、确定岩性尖灭位置以及区分相邻两独立礁体的波阻抗响应。川东北地区实际资料应用效果证实,FIHDI法可以避免受到地震数据失真的低频和高频成分的影响,保持反演结果的稳定性和可靠性,与测井计算的波阻抗模型在整体趋势和细节特征上均保持了较好的一致性,具备刻画薄层波阻抗异常细节特征的能力,能够为地层岩性识别、岩相分析、储层描述提供可靠的高分辨率地震波阻抗数据。

In combination with the spectral inversion method of sparse-spike reflection coefficients based on compressed sensing (referred to as CSSRI) and the conventional direct-inversion method of seismic wave impedance in the frequency domain shortly called FIDI,a direct-inversion method of high-resolution seismic impedance is proposed in the frequency domain,called FIHDI for short here.The proposed method inherits the high-resolution performance of CSSRI that can broaden the frequency bandwidth of seismic data,and retains the reliability,stability and computing simplicity of the conventional direct-inversion method for seismic impedance in the frequency domain.The results using the theoretical model data testing show that FIHDI method and the conventional direct-inversion method in frequency domain can finely depict the stratigraphic overlap relationship of the complex reef-bank model,locate the lithologic pinchout position and distinguish the seismic impedance response of two adjacent independent reef bodies.The application case of the real seismic data proves that the inversion results of FIHDI can avoid the influence of the contaminated low frequency and high frequency information to maintain the stability and reliability and in good consistency with the whole trend and details of wave impedance from well-logging,which can provide reliable high-resolution seismic impedance for lithology identification,lithofacies analysis and reservoir chracterization.

国家科技重大专项(2011ZX05005-005-005)资助。