薄互层型油气储层同步挤压变换域分析方法

Characterization of thin interbedded reservoir using synchrosqueezing transform

薄互层型油气储层是陆相沉积盆地主要储层类型之一。研究如何利用地震资料刻画和预测薄互层油气储层,对中国油气勘探与开发具有重要意义。介绍了由三参数小波变换而得到的同步挤压三参数小波变换及其在薄互层型储层分析和地震资料谱分解中的应用。与三参数小波变换相比,同步挤压三参数小波变换在时间尺度域增加了对三参数小波变换的小波系数的重排操作,以提高时频分辨率。利用同步挤压三参数小波变换进行薄互层储层分析的方法既可以研究薄互层组的整体特性,也可以表征其组内的结构。与Morlet小波变换等常用的时频分析方法相比,该方法有更高的时频分辨率,能更好地刻画薄互层的整体特性及其组内的结构。合成地震记录和实际算例表明,同步挤压三参数小波变换对于地下地质体及不同厚度的河道和叠置的河道的刻画比其它相关变换的结果更为清晰和可靠。

The thin interbedded reservoir is one of the main types of hydrocarbon reservoirs in the continental sedimentary basin. Studying how to use seismic data to characterize and predict thin interbedded oil and gas reservoirs is of great significance to China＇s oil and gas exploration and development. In this study, we proposed a synchrosqueezing three-parameter wavelet transform （SSTPWT） algorithm based on the three-parameter wavelet transform （TPWT） and applied the proposed algorithm to characterize thin interbedded reservoirs. Unlike the TPWT, the proposed transform involves an operation to rearrange the wavelet coefficients of the three-parameter wavelet transform in the time domain to improve the time-frequency （TF） resolution. This proposed method can help characterize both the total properties and inner structures of the thin interbedded reservoir.Test results on both synthetic and field data showed that, compared with commonly used TF transforms such as CWT using the Morlet wavelet as the basic wavelet, the proposed method achieved a higher TF resolution and characterized channels with different thicknesses more clearly.