珠江口盆地L凹陷裂陷期始新统文昌组沉积充填模式

发布时间：2018-11-25 19:32

【摘要】：珠江口盆地L凹陷始新统文昌组处于勘探初期,钻井资料较少且分布不均,基于多井多资料的常规沉积相研究方法受到限制,对于层序地层和沉积体系没有系统研究,本次研究充分利用地震、测井以及岩心资料,在全区开展地震相研究工作,井震结合对沉积相展布进行研究,建立裂陷期文昌组沉积演化模式。结果表明:L凹陷裂陷期文昌组划分为3个三级层序,8个体系域;根据三级层序体系域内部地震反射外部形态和内部反射特征差异,识别出充填、席状、楔形、块状、丘形5种地震相类型;通过分析岩心相、测井相以及各种地震相特征,井震结合将地震相转为沉积相,识别出辫状河三角洲、扇三角洲、湖相等沉积相;初始裂陷期为小盆小湖模式,凹陷分割性较强,主要为近源扇三角洲粗碎屑沉积,强烈裂陷早期为大盆浅湖模式,洼陷连通,主要为辫状河三角洲沉积,强烈裂陷中晚期为大盆深湖模式,主要对应半深湖泥岩沉积,弱裂陷期主要为大盆浅湖模式,主要对应大规模长轴辫状河三角洲充填沉积体系。
[Abstract]:The Wenchang formation of Eocene in the L depression of Pearl River mouth basin is in the early stage of exploration, the drilling data are less and distributed unevenly, the conventional sedimentary facies research method based on multi-well and multi-data is limited, and there is no systematic study on sequence stratigraphy and sedimentary system. In this study, seismic facies research was carried out in the whole area by making full use of seismic, well logging and core data. The sedimentary evolution model of Wenchang formation in rift period was established by combining well earthquakes with sedimentary facies distribution. The results show that the Wenchang formation in the rift period of L depression is divided into three third-order sequences and eight system tracts. According to the internal seismic reflection external morphology and internal reflection characteristics of the third order sequence system tract, five types of seismic facies are identified: filling, sheet, wedge, block and mound. By analyzing the characteristics of core facies, logging facies and various seismic facies, the well and earthquake facies are transformed into sedimentary facies, and the braided river delta, fan delta and lake sedimentary facies are identified. The initial rift stage is a small basin and small lake model, and the sag has a strong divisibility, which is mainly composed of coarse clastic deposits in the near-source fan delta, a large basin and shallow lake model in the early stage of the strong rift, and connected sag, mainly braided river delta deposition. In the middle and late period of strong rifting, it is a deep lake model of large basin, which mainly corresponds to the mudstone deposit of semi-deep lake, while the weak rift stage is mainly a model of shallow lake in large basin, which corresponds to the filling system of large scale braided river delta of long axis.
【作者单位】：中国石油大学(北京)地球科学学院;西安石油大学;中海石油深圳分公司;中国石化华东分公司;
【基金】：国家自然科学基金项目(编号:41672098)资助~~
【分类号】：P512.2;P618.13

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