小波分析在松辽盆地北部高分辨率层序地层学中的应用

THE APPLICATION OF WAVELET ANALYSIS TO HIGH-RESOLUTION SEQUENCE STRATIGRAHIC DIVISION IN NORTHERN SONGLIAO BASIN

以松辽盆地北部英台—大安地区英37井姚家组二三段地层划分为例,分析一维连续小波变换在高分辨率层序划分中的适用性。通过对GR测井曲线进行Morlet小波变换,将测井曲线信号与深度的关系转换为深度与尺度域的变化关系,得到不同尺度上的小波系数曲线,然后建立最佳尺度因子下的小波系数曲线的周期性振荡特征与各级层序界面的对应关系。划分结果表明:小波变换适用于中期及短期基准面旋回的划分,为高分辨率层序地层学研究提供了一个新的思路。

Taking sequence stratigraphy division of K1y2＋3 group in Yingtai-Da＇an region of northern Songliao Basin as an example,the author analyzed the applicability of one-dimensional continuum wavelet conversion in high-resolution sequence stratigraphy division.Wavelet coefficient curves of different cycle orders can be obtained through Morlet wavelet analysis of GR curve,with whose conversion the logging data were expanded from depth space into-depth-scale space.Researches were conducted on the relationship between the periodicity oscillation characteristics of optimum scale wavelet coefficient curves and the boundaries of different level cycles,and the results were used to the identification and division of the boundaries of the sequence.It is shown that wavelet conversion is suitable for the division of mid-term base-level cycles and short-term base-level cycles,and it provides a new idea for the division of high-resolution sequence stratigraphy.