三角洲—浅海沉积体系泥质沉积规律模拟实验——以琼东南盆地崖南凹陷为例  

Simulation experiment of argillaceous sedimentary law of delta-shallow sea sedimentary system:A case study of Yanan Sag,Qiongdongnan Basin

作　　者：屈童 高岗[1,2] 徐新德 王瑞[1,2] 甘军 梁刚 游君君 QU Tong;GAO Gang;XU Xinde;WANG Rui;GAN Jun;LIANG Gang;YOU Junjun(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Zhanjiang Branch,CNOOC China Limited,Zhanjiang 524057,Guangdong,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中海石油(中国)有限公司湛江分公司,广东湛江524057

出　　处：《岩性油气藏》2022年第1期24-33,共10页Lithologic Reservoirs

基　　金：中海油“十三五”油气资源评价项目(编号:YXKY-2018-KT-01);自然资源部项目“中海油矿权区油气资源评价”(编号:2017YQZYPJ0109)联合资助。

摘　　要：三角洲—浅海沉积体系由于同时具有陆源有机及海洋有机质备受众多学者的关注,近年来南海地区油气勘探实践表明崖城组陆源海相泥岩是油气生成的重要来源之一,但由于深水区烃源岩埋深较大、现有钻井较少,极大地限制了该地区烃源岩研究与勘探进展。为了对泥质沉积物沉积与分布规律进行研究,本文以琼东南盆地崖南凹陷崖城组地质背景为基础,设计沉积模拟实验,对沉积物沉积过程进行观察,并对沉积体进行取样,测定样品粒度组成,结合定性观察与定量对比,对三角洲—浅海沉积体系泥质沉积物的沉积规律进行探究,对陆源海相烃源岩的优势发育部位进行揭示。研究结果表明,由物源向浅海方向,沉积物的泥质含量呈整体增大的趋势,在三角洲前缘斜坡处由于水动力条件的骤降出现突增,但沉积物的总量呈先增大后减小的趋势,使得泥质沉积物的总量向深水方向呈减少趋势;三角洲前缘斜坡—浅海沉积范围是泥岩发育的优势区域,在三角洲沉积体内局部低地势、弱水动力条件的部位也可沉积并保存泥质沉积物;地形坡度的增大有利于泥质沉积物向深水区搬运。三角洲前缘—浅海区是泥质沉积物堆积的主要部位,即近海盆地的近岸地区,这对琼东南盆地深水区陆源海相烃源岩优势发育部位的预测提供了重要依据与指导。The delta-shallow sea sedimentary system has attracted the attention of many scholars due to its combination of terrestrial organic matter and marine organic matter.In recent years,oil and gas exploration practices in the South China Sea have shown that terrigenous marine mudstone of Yacheng Formation is one of the important sources of oil and gas generation.The source rocks are buried deep and there are few existing wells,which greatly limits the research and exploration progress of source rocks in this area.In order to study the deposition and distribution of argillaceous sediments,based on the geological background of Yacheng Formation in Yannan Sag,Qiongdongnan Basin,a sedimentary simulation experiment was designed to observe the sedimentary process,and the sedimentary bodies were sampled to determine the particle size composition of the samples.Combined with qualitative observation and quantitative comparison,the sedimentary law of argillaceous sediments in delta shallow sea sedimentary system was explored,and the dominant development position of terrestrial marine source rocks was revealed.The results show that from the provenance to the shallow sea,the argillaceous content of sediments increases as a whole.At the delta front slope,the argillaceous content increases suddenly due to the sudden drop of hydrodynamic conditions,but the total amount of the sediments increases first and then decreases,which makes the total amount of the argillaceous sediments decrease to the deep water.The delta front slope-shallow sea sedimentary area is the dominant area for the development of terrestrial marine source rocks,and argillaceous sediments can also be developed in the low-lying and weak hydrodynamic parts of the delta sedimentary body.The increase of terrain slope is conducive to the transportation of argillaceous sediments to the deep-water area.The delta frontshallow sea area is the main part of argillaceous sediment accumulation,that is,the nearshore area near the sea basin,which provides an important basis and g

关 键 词：三角洲—浅海沉积体系 陆源海相烃源岩 泥质沉积物 沉积模拟实验 优势发育区 琼东南盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]