基于测井曲线频谱分析米氏旋回特征——以柴西尕斯地区上干柴沟组为例

柴达木盆地保存了巨厚的完整连续的新生代沉积层序,为研究沉积旋回提供了良好的场所.位于盆地西部尕斯地区的上干柴沟组是典型的陆相碎屑岩地层之一,由多层砂岩和泥岩频繁相互叠置而成,高精度的沉积旋回研究鲜有讨论.综合运用频谱及滤波方法来深入分析地处柴西尕斯地区的YP2、YQ17井自然伽马测井数据.结果显示,天文轨道周期比值和中...

Characteristics of Mirankovich Cycles Based on the Spectrum Analysis of Logging Curve:A Case Study of Shangganchaigou Formation in Gas Area,Western Qaidam Basin

The thick and unbroken Cenozoic sedimentary sequences are preserved in the Qaidam Basin, which provides a good place for studying the sedimentary cycle. The Shangganchaigou formation, located in Gas area in the west of the basin, is one of the typical continental clastic strata, which is composed of multi-layered sandstone and mudstone superposition each other frequently. But there is little discussion about its high precision sedimentary cycle. The spectrum and filtering methods are comprehensively used to analyze the natural gamma logging data of Well YP2 and Well YQ17 in the Gas area of the western Qaidam Basin. The results show that there is a good correspondence between the ratio of the astronomical orbital period and the ratio of the thickness of medium and high-frequency cycles. On this basis, combining the factors of deposition rate and paleoclimate, it is found that the Milankovitch cycle is relatively intact in the strata of the Shangganchaigou Formation in Gas area. Among them, the thickness variation of the formation cycle caused by the short eccentricity period is 10.48-11.26m. The thickness variation of the formation cycle caused by a long period of the axial slope is 5.85-5.87m. The thickness variation of the formation cycle caused by a short period of the axial slope is 4.22-4.57m. The thickness variation of the formation cycle caused by the precession period is 2.42-2.61m. The thickness variation of the formation cycle caused by the short precession period is 1.97-2.12m.