小波变换用于测井沉积旋回界面划分研究

Demarcation of Sedimentary Cycle Based on Wavelet Transform of Logging Data

以东营凹陷某井为例,选取尺度与周期有对应关系的Morlet小波基函数,对SP测井曲线进行小波变换,将一维测井数据拓展为二维深度-尺度空间,可探测到不同尺度沉积旋回的分界面,与传统的旋回界面划分结果基本一致。其地质学意义在于,由多个不同尺度(周期)沉积旋回叠加测井曲线,通过时频变换,被分解成各自独立的单一尺度的旋回,尺度因子的大小反映了地层沉积周期的长短。这也为沉积旋回的定量划分提供了一种新的思路。

Logging data including a great amount of geological information became me main sources applied to study the demarcation of sedimentary cycle. The data of SP well logging curve from a well in Dongying sag are processed through Morlet wavelet transfer whose scale corresponds to the period of the sedimentary cycle for case study. The result shows that the boundaries of sedimentary cycle in different scales can be detected through expanding one dimensional logging data into that of two dimensional depth-scale space, and are in agreement with that obtained through the traditional method. In geology it means that the logging curve added by sedimentary cycles in different scales can be decomposed into cycles in single scale independent of each other by time and frequency transfer, and the scale coefficient corresponds to the period of sedimentary cycle. All these researches provide a new clew for the quantitative classification of the cycle.