靖安油田延长组米兰柯维奇沉积旋回分析

Analysis of Milankovitch Cycles of Yanchang Formation in Jing′an Oilfield

对米兰柯维奇旋回理论进行了概述,认为米兰柯维奇天文轨道参数所诱导的旋回沉积序列普遍存在于地质记录中。用小波分析对鄂尔多斯盆地靖安油田延长组储层测井曲线数据进行了预处理,采用快速傅里叶变换(FFT)进行了频谱分析,发现该储层中的沉积旋回主要受古气候变化的控制,由此确定了储层旋回厚度变化的周期并分析了米兰柯维奇旋回各因素对延长组储层旋回的影响,其中偏心率对该区沉积旋回的影响最大。

This paper introduces the principles of Milankovitch cycle and its significance in geology application.The natural gamma logging curve of Yanchang Formation in Jing′an Oilfield,Ordos Basin could be used to discrete the original gamma through wavelet transform and fast Fourier transform(FFT),providing spectral analysis results.It has been recognized in the study that the Milankovitch cycle existed in Yanchang reservoir and confirmed that the main sedimentary cycles are 123.0,95.0,46.0,36.2,21.3,17.8 ka,corresponding with the eccentricity,the obliquity cycle and the precession cycle of Milankovitch cycle.Among the three control factors,the eccentricity cycle has a more important effect on the Yanchang reservoir of Milankovitch cycle.