论文部分内容阅读
本文从含流体孔隙介质中的地震波场的衰减理论出发,对常规的频率衰减分析技术中的“低频阴影”和“频率衰减梯度”分析方法进行了改进,提出了一种高精度的频率衰减分析技术。首先,通过引入三参数小波变换和时频聚焦准则,发展了一种基于自适应三参数小波变换的高精度时频分析方法,其不仅具有很高的时—频分辨率(有利于“低频阴影”分析),而且其频谱只有一个峰,旁瓣比较小(有利于“频率衰减梯度”分析)。其次,采用基于最小二乘法的Nelder-Mead非线性算法对频谱的衰减部分进行拟合计算,可以准确地计算衰减系数,提高了“频率衰减梯度”的计算精度。实际资料的计算结果表明,本文提出的综合“低频阴影”和“频率衰减梯度”方法的频率衰减分析技术能够有效地圈定碳酸盐岩鲕滩储层的发育区域,且两种方法具有很好的一致性,有效地提高了储层预测的可靠性,从而降低了勘探风险。
In this paper, based on the attenuation theory of seismic wavefield in fluid-porous media, the “low frequency shadow” and “frequency attenuation gradient” analysis methods in the conventional frequency attenuation analysis are improved, and a high precision Frequency attenuation analysis technology. Firstly, by introducing three-parameter wavelet transform and time-frequency focusing criterion, a high-precision time-frequency analysis method based on adaptive three-parameter wavelet transform is developed, which not only has high time-frequency resolution Shaded “analysis), and its spectrum has only one peak with a small sidelobe (favoring the” frequency decay gradient "analysis). Secondly, the Nelder-Mead non-linear algorithm based on the least square method is used to fit the attenuation part of the spectrum, which can accurately calculate the attenuation coefficient and improve the calculation precision of the frequency attenuation gradient. The calculation results of actual data show that the proposed frequency attenuation analysis method of integrated low frequency shadowing and frequency attenuation gradient method can effectively delineate the development zones of carbonate oolitic beach reservoirs, The method has good consistency and effectively improves the reliability of reservoir prediction, thus reducing the exploration risk.