信噪比对波阻抗反演效果影响研究

Influence of SNR on wave impedance inversion results

波阻抗反演可以得到储层的物性参数并对储层进行预测,为油气田的勘探开发提供直接反映岩性、流体的基础资料.而地震资料是波阻抗反演最重要的基本数据,它必须具备较高的质量,在此方面很多学者大多从实际应用的角度定性分析道集品质对波阻抗反演的影响,但这种定性分析并不能对地震资料的品质提供量化的分析,因此本文利用水平层状模型,从定量的角度讨论了信噪比对波阻抗反演效果的影响,这将为实际应用中对波阻抗反演结果的解释起到指导作用.研究结果表明,对于叠后波阻抗反演,地震资料信噪比至少要达到21,其反演结果才具有一定的可靠性;叠前波阻抗反演对资料信噪比的要求则更高,信噪比降低对波阻抗边界处的影响比地层内大.

We can use wave impedance inversion technique to get physical parameters of reservoir and predict reservoir, so as to provide a direct reflection of lithology and fluid basic information for exploration and development of oil and gas fields. Seismic data is the most important basic data in the wave impedance inversion, and it must have a high quality. Many scholars mostly qualitatively analyze influence of gathers quality on wave impedance inversion results from the perspective of practical application, but it can not provide quantitative analysis for seismic data quality. So horizontally layered models are used to discuss the influence of SNR on wave impedance inversion results in terms of quantitative analysis in this paper, it can play a guiding role for the interpretation results of wave impedance inversion in practical application. The research results show that only the SNR of seismic data reaches at least 2 ： 1, its inversion results will contain a certain reliability for post-stack wave impedance inversion; pre-stack wave impedance inversion requires seismic data with more high SNR, when the SNR reduces, the wave impedance boundary suffers more severe impact than strata.