渤海湾盆地沾化凹陷古近系沙三下亚段旋回地层学分析及地层划分  

Cyclostratigraphy analysis and stratigraphic division of lower Sha-3 member of Paleogene in Zhanhua Sag,Bohai Bay Basin

作　　者：方旭庆[1] 钟骑 张建国[2] 李军亮[3] 孟涛[3] 姜在兴[2] 赵海波 FANG Xuqing;ZHONG Qi;ZHANG Jianguo;LI Junliang;MENG Tao;JIANG Zaixing;ZHAO Haibo(Manage Center of Oil and Gas Exploration,Shengli Oilfield Company,Sinopec,Dongying 257001,Shandong,China;College of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China;Research Institute of Exploration and Development,Shengli Oilfield Company,Sinopec,Dongying 257015,Shandong,China)

机构地区：[1]中国石化胜利油田分公司油气勘探管理中心,山东东营257001 [2]中国地质大学(北京)能源学院,北京100083 [3]中国石化胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《岩性油气藏》2024年第3期19-30,共12页Lithologic Reservoirs

基　　金：国家自然科学基金项目“天文旋回约束下的湖相泥页岩沉积作用:以济阳坳陷始新统为例”(编号:41772090)资助。

摘　　要：湖相细粒沉积多具有连续性,能记录和保存显著的天文旋回信号,是进行天文旋回分析的理想地层。通过对渤海湾盆地沾化凹陷重点井沙三下亚段自然伽马数据进行MTM频谱分析和FFT进化谐波分析,建立了“浮动”天文年代标尺,并在单井上进行了天文旋回地层划分及连井地层对比,为全区搭建了地层格架。研究结果表明:(1)渤海湾盆地沾化凹陷沙三下亚段记录了显著的天文旋回信号,匹配出最优沉积速率为9.0×103cm/Ma;由长偏心率、短偏心率、斜率和岁差周期产生的旋回地层厚度分别为42.3 m,9.0 m,2.4~4.7 m和1.3~1.9 m;(2)沙三下亚段比较稳定的记录了6个长偏心率旋回、25个短偏心率旋回,可将短偏心率曲线作为地层划分依据来进行高精度地层对比。(3)运用天文旋回理论进行岩相发育规律、岩相空间配置关系的预测,可为湖盆沉积中心页岩油气地质“甜点”的精细勘探提供依据。Lacustrine fine-grained sediments often have continuity and can record and preserve significant astronomical cycle signals,making them ideal strata for astronomical cycle analysis.MTM spectrum analysis and FFT evolutionary harmonic analysis were conducted for natural gamma data of the lower Sha-3 member of key wells in Zhanhua Sag,Bohai Bay Basin,a“floating”astronomical timescale was established,astronomical cyclostratigraphic division of single well and well-tie stratigraphic correlation were carried out,and the stratigraphic framework was established.The results show that:(1)Significant astronomical cycle signals were recorded in the lower Sha-3 member in Zhanhua Sag,and the optimal sedimentation rate was matched to be 9.0×103 cm/Ma.The cycle thicknesses corresponding to long eccentricity,short eccentricity,obliquity and precession cycle are 42.3 m,9.0 m,2.4-4.7 m and 1.3-1.9 m,respectively.(2)Six long eccentricity cycles and 25 short eccentricity cycles were stably recorded in the lower Sha-3 member,and the short eccentricity curves can be used as the stratigraphic division interface for high-precision stratigraphic correlation.(3)The application of astronomical cycle theory to predict the development patterns and spatial configuration relationships of lithofacies can provide a basis for the precise exploration of geological“sweet spots”of shale oil and gas in the sedimentary center of the lake basin.

关 键 词：湖相细粒沉积 天文年代标尺 天文旋回 高精度地层对比 长偏心率旋回 短偏心率旋回 沙三下亚段 古近系 沾化凹陷 渤海湾盆地 

分 类 号：TE121.34[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]