基于沉积特征分段旋回地层学研究方法探讨及应用—以西部凹陷西78井沙四上段为例

旋回地层学分析为高精度地层研究提供了有效手段,但沉积速率不稳定严重制约了旋回地层学的应用。本文提出了基于沉积特征分段的旋回地层学分析方法来规避沉积速率不稳定的影响。本文以辽河西部凹陷中西78井沙四上段为例来阐述基于沉积特征分段的旋回地层学分析方法的过程及其优势,通过对其沉积记录进行了基于沉积特征的分段和对各段自然伽马测井数据进行小波时频分析和频谱分析,识别出了较为显著的米兰科维奇沉积旋回,取得了较好的应用效果。此方法为复杂地质条件下的沉积地层进行旋回地层学分析提供了新的思路。

The Discussion and Application of Cyclostratigraphy Research on Subsection Divided by Sedimentary Features: a case study in upper Section of 4th of Well Xi78 in West Depression

Cyclostratigraphy provides a useful method in high precise research in stratigraphy while the unstable of deposition rate is heavily restrict the application of Cyclostratigraphy analysis. In the paper, Cyclostratigraphy analysis on subsection divided by sedimentary features is proposed to avoid the influence of the unstable deposition rate. Well Xi78 in West Depression is taken as an example to explain the application and advantageous of Cyclostratigraphy research on Subsection divided by sedimentary features, the upper section of 4th is divided into several segments based on the sedimentary features, spectral analysis and wavelet time frequency analysis method were conducted on the natural gamma ray logging data of each segment, relatively significant sedimentary cycles forced by Milankovitch periods were identified, application effect is remarkable. The method provides a new idea for the application of Cyclostratigraphy analysis in complex geology background.