【作者】 王志坤；

【导师】 钟建华；

【作者基本信息】 中国石油大学 ， 矿物学、岩石学、矿床学， 2008， 博士

【摘要】 本文立足于高邮凹陷勘探实践,运用层序地层学理论对研究区进行低频层序地层划分;在层序格架范围内对沉积体系和沉积相进行了研究;重点对戴南组地层进行了高频层序研究;并论述了高频层序的识别方法、控制因素;最后提出了三角洲相高频层序地层定量划分的方法。运用经典层序地层学理论,综合岩芯、测井和地震等资料,建立了高邮凹陷上白垩统—新近系的层序地层框架,划分出相对盆地而言的2个一级层序、4个二级层序、11个三级层序。在等时层序地层格架内,研究了各层序的沉积相展布及演化规律,提出了本区的沉积相模式。研究区在层序SQ5、SQ6和SQ7 (戴南组)沉积期主要发育三角洲沉积体系,SQ8 (三垛组)沉积期发育河流相沉积体系。重点对戴南组地层进行了高频旋回层序研究,应用Fischer图解、测井曲线频谱分析和小波分析等方法对高频旋回进行了识别。研究认为Fischer图解并不适用于陆相碎屑岩地层的高频旋回识别;对处于构造平稳期的以三角洲前缘沉积为主的地层,测井曲线频谱分析和小波分析能有效识别其中的高频旋回。对测井曲线频谱分析结果表明地层中很好的保存了米兰科维奇旋回,偏心率长周期控制的地层旋回厚度约100m;偏心率短周期控制的地层旋回厚度约25m;岁差周期控制的地层旋回厚度约5m,由此计算本区的沉积速率为25cm/kyr。在层序划分过程中,应用小波振幅谱和复小波相位谱,确定了适用于戴南组地层的Morlet小波尺度与高频旋回层序级别的对应关系: 800尺度小波系数曲线对应四级层序;200尺度小波系数曲线对应五级层序;40尺度小波系数曲线对应六级层序。分析了高频层序的主控因素,认为高频层序受控于米兰科维奇天文周期。确定了高频层序划分方案。更多还原

【Abstract】 Based on the exploration on Gaoyou Sag, directed by the principles of sequence stratigraphy, and within the framework of sequence stratigraphy, the paper took study of sedimentary system and facies, and especially study of high-frequency sequence stratigraphy on Dainan Formation. At the same time, the paper found controlling factors and the discriminating method on high-frequency sequence stratigraphy, and finally developed a quantitative method to discriminating high-frequency sequences of delta.Directed by the principles of classical sequence stratigraphy, combined with core, well logging and seismic data, etc., the sequence framework from Eogene to upper Crataceous in Gaoyou Sag was set up and divided into 2 primary sequences, 4 secondary sequences and 11 tertiary sequences for the basin.Within the equal-time sequence framework, distribution of sedimentary facies and their evolution rule were analyzed, and the sedimentary mode was proposed. Delta deposit system was mainly developed in Sequence 5, Sequence 6, and Sequence 7 (such as Dainan Formation), and fluvial deposit system was mainly developed in Sequence 8 (such as Formation Sanduo).It was mainly done on the study of high-frequency cycle sequence in Dainan Formation. Applying the method of Fischer Graphy, spectrum analysis of the log, wavelet analysis to discriminate high-frequency cycle, the study showed that the Fischer graphy was not applicable to high-frequency cycle discrimination of continental clastic rock, but as the main layer of the delta front sedimentary during the stable period of structure, the log spectrum analysis and wavelet analysis could efficiently discriminate high-frequency cycle in it. The result of the log spectrum analysis indicated Milankovitch cycle was well kept in stratum, and the thickness of the formation cycle long-period controlled by eccentricity was about 100m, and the thickness of the formation cycle short-period controlled by eccentricity was about 25m and the thickness of the formation cycle controlled by precession was only about 5m, consequently, deposition rate in study area was 25cm/ka.Through the application of wavelet amplitude spectrum and phase spectrum of multiple wavelet in sequence division, the paper confirmed the correspondence relationship between Morlet wavelet dimension and high-frequency sequence cycle level——800-scale wavelet coefficients corresponding period of the medium-term cycle, 200-scale wavelet coefficients corresponding period of the short-term cycle, 40-scale wavelet coefficients corresponding period of the ultra-term cycle.The paper analysed the master factor of high-frequency cycle, and it was thought that high-frequency sequence cycle was controlled by Milankovitch cycle, thus the division method was confirmed.更多还原