陆丰地区古近系恩平组沉积演化特征及沉积模式

发布时间：2018-03-06 10:00

本文选题：断陷湖盆　切入点：沉积相　出处：《中国石油大学学报(自然科学版)》2017年05期 　论文类型：期刊论文

【摘要】：在岩心观察的基础上,结合地震、钻井、测井、薄片等资料,对珠江口盆地陆丰地区古近系恩平组沉积特征进行研究,并结合构造背景、古地貌建立其沉积相模式。研究表明:陆丰地区恩平组裂陷Ⅱ幕发育4个三级层序,主要发育3类沉积相,即扇三角洲、辫状河三角洲和湖泊;恩平组沉积早期,研究区发育的3个洼陷互不连通,洼陷陡坡带发育扇三角洲,缓坡带发育辫状河三角洲。沉积中期,洼陷主控断裂活动强度由南向北增强,沉降中心和沉积中心逐渐向北迁移,洼陷相互连通,主物源区经历了由盆内基底凸起和东沙隆起向北部隆起带的转换,以发育大范围展布辫状河三角洲、滨浅湖滩坝为特色。沉积晚期,主控断裂活动减弱,湖盆淤浅萎缩,四周辫状河三角洲进积,发育薄煤层;主控断裂活动为沉积物提供可容空间,控制洼陷几何形态,一级断层转换带控制主物源方向,二级断层转换带分割主物源通道,影响沉积砂体再分配,沉积体系发育与砂体分布则与古地貌密切相关;滨浅湖滩坝是研究区最有利的储集相带,其次是扇三角洲前缘水下辫状河道及河口砂坝,最末为辫状河三角洲前缘水下分流河道及河口砂坝。
[Abstract]:On the basis of core observation, combined with seismic, drilling, logging, thin slice and other data, the sedimentary characteristics of the Paleogene Enping formation in Lufeng area, Pearl River mouth basin, are studied and combined with the tectonic background. The sedimentary facies model of paleogeomorphology is established. The results show that there are four third-order sequences developed in the second episode of the rift of the Enping formation in Lufeng area, which are mainly three types of sedimentary facies, namely fan delta, braided river delta and lake, the early sedimentary stage of the Enping formation. The three depressions developed in the study area are disconnected. Fan deltas are developed in steep slope zones and braided river deltas are developed in gentle slope zones. In the middle sedimentary period, the activity intensity of the main faults in the sag increases from south to north, and the subsidence center and sedimentary center gradually migrate northward. The sag is connected to each other, and the main provenance area experienced the transition from the basement uplift in the basin and the Dongsha uplift to the northern uplift zone, characterized by the development of a wide range of braided river deltas and shored-shallow lake beach dams. In the late sedimentary period, the main faulting activities weakened. The lake basin is shallowly atrophied, the braided river delta is precession and thin coal seam is developed, the main fault activity provides the accommodation space for the sediment, the geometric shape of the sag is controlled, and the primary fault transition zone controls the direction of the main material source. The secondary fault transition zone divides the main provenance channel and affects the redistribution of sedimentary sand bodies, and the development of sedimentary system and distribution of sand bodies are closely related to paleogeomorphology, and shoreline beach dam is the most favorable reservoir facies zone in the study area. The second is the fan delta front underwater braided channel and estuary bar, and the last is the braided delta front underwater distributary channel and estuary bar.
【作者单位】：中南大学地球科学与信息物理学院;有色金属成矿预测与地质环境监测教育部重点实验室(中南大学);中海石油(中国)有限公司深圳分公司;
【基金】：国家科技重大专项(2011ZX05023-001) 中国海洋石油总公司综合科研项目(YXKY-2015-SZ-02)
【分类号】：P618.13

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