摘要
由天体轨道周期性变化引起气候改变而被记录在沉积地层中的米兰科维奇旋回,具有时间域上的等时性特征,是实现高频沉积旋回等时划分与对比的有效途径。基于米兰科维奇理论,以准噶尔盆地玛湖凹陷百口泉组地层为研究对象,对3口井自然伽马和电阻率测井曲线进行频谱分析。将测井曲线经过滤波处理后提取出的短偏心率周期99.0ka和短斜率周期40.5ka的滤波曲线,作为五级层序沉积旋回和六级层序沉积旋回的参考曲线,对百口泉组地层进行高频沉积旋回的划分与对比,建立玛湖凹陷百口泉组地层沉积旋回对比格架。结果表明:百口泉组地层保存完整的米兰科维奇沉积旋回,旋回主要由偏心率(99.0ka)和斜率(40.5ka)周期控制,偏心率和斜率周期引起的地层厚度分别为6.49~7.05和2.56~2.98m,平均沉积速率为6.76cm/ka。该研究结果为测井曲线在高频地层层序识别与划分上的应用提供新的方法,为层序地层划分研究提供参考。
The Milankovitch cycle,which is recorded in the sedimentary strata caused by the cyclical change of the celestial orbit,has the isochronal characteristics in the time domain and is an effective way to realize the division and comparison of the high frequency deposition cycles.Based on the theory of Milankovic,the Baikouquan formation in the Mahu depression,Junggar basin,is used to analyze the natural gamma and resistivity logs of the three wells.The results show that the complete Milankovitch deposition cycle is maintained in the Baikouquan formation,and the cycles are mainly controlled by eccentricity（99.0 ka）and slope（40.5 ka）.The thickness of the strata caused by eccentricity and slope period is6.49~7.05 and 2.56~2.98 m,the average deposition rate is 6.76 cm/ka.The filter curves of the short eccentricity period 99.0 ka and the short slope period of 40.5 ka extracted by the logging curve are taken as the reference curves of the five-order sequence deposition cycle and the sixth-order sequence deposition cycle.And the comparison of the high-frequency deposition cycles are carried out to establish the sedimentary cycle of the Baikouquan formation in the Mahu depression.In this paper,a new method is proposed for logging identification and division of high frequency stratigraphy,which provides a reference for sequence stratigraphic division.
出处
《东北石油大学学报》
CAS
北大核心
2017年第5期54-61,共8页
Journal of Northeast Petroleum University
基金
国家科技重大专项(2016ZX05027-02-007)
国家自然科学基金项目(41302096
41172106)
关键词
米兰科维奇旋回
沉积旋回
频谱分析
滤波分析
沉积速率
百口泉组
玛湖凹陷
Milankovitch cycle
sedimentary cycles
spectral analysis
filtering analysis
deposition rate
Baikouquan formation
Mahu depression
