三角洲—浅海沉积体系陆源有机质沉积模拟实验研究——以琼东南盆地崖南凹陷崖城组为例  

Sedimentary Simulation Experiment Study on the Distribution of Terrestrial Organic Matter in the Delta-shallow Sea Sedimentary System:A case study of the Yacheng Formation in the Yanan Sag,Qiongdongnan Basin

作　　者：屈童 高岗[1,2] 徐新德 黄志龙[1,2] 甘军 梁刚 游君君 QU Tong;GAO Gang;XU XinDe;HUANG ZhiLong;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;CNOOC China Limited,Zhanjiang Branch,Zhanjiang,Guangdong 524057,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：《沉积学报》2023年第2期584-600,共17页Acta Sedimentologica Sinica

基　　金：中海油“十三五”油气资源评价项目(YXKY-2018-KT-01);“十三五”全国油气资源评价项目中海油矿权区油气资源评价(2017YQZYPJ0109)。

摘　　要：陆源有机质在三角洲—浅海沉积体系中扮演着重要的角色,越来越多的深水区油气勘探实践发现存在陆源有机质的贡献,在琼东南盆地崖城组烃源岩甚至以陆源有机质为主,这引起了诸多学者的关注,但由于深水区烃源岩埋深较大、钻井较少,限制了该地区烃源岩研究及勘探进展。为明确陆源有机质分布特征,以琼东南盆地崖南凹陷崖城组地质背景为基础,设计陆源有机质沉积的水槽实验,用“正演”的方法对陆源有机质沉积过程进行观察,并对沉积结果进行取样,对样品进行粒度分析及TOC分析,结合大量分析测试数据及已有的现代河口陆源有机质分布研究实例,对陆源有机质分布特征进行分析,并建立分布模式。结果表明,由物源向深水区方向,陆源有机碳含量呈先增大后减小的趋势,在三角洲前缘—浅海过渡区出现最大值,古地形坡度越缓,水动力环境越弱,三角洲发育范围受限,陆源有机质搬运最远距离向物源方向迁移。Terrestrial organic matter plays an important role in the delta-shallow sea sedimentary system.More and more oil and gas exploration practices find the contribution of terrestrial organic matter in deep-water areas.In the Yacheng Formation of the Qiongdongnan Baisn,the source rocks are dominated by terrestrial organic matter,which has attracted the attention of many scholars.However,due to the deep buried depth of the source rock and the lake in the deep-water area,the research and exploration progress of the source rock in this area is greatly restricted.Based on the geological background of the Yacheng Formation in the Yanan Sag,Qiongdongnan Basin,this study designed a flume experiment of terrestrial organic matter,which is a“forward modeling”method,to observe the deposition process of terrestrial organic matter and sample the sedimentation results.Particle size and total organic carbon(TOC)analyses were carried out on the samples,establishing a terrestrial organic carbon content prediction model through a large amount of analytical test data and applying the model to an actual research area with less data.We combine the qualitative observation of the experimental process and quantitative calculation results to establish a ter⁃restrial organic matter distribution pattern.The results show that the terrigenous organic matter is mainly deposited in the low-lying parts with a weak hydrodynamic force.From the source area to the deep water area,due to the interac⁃tion between the river and the sea water,the transport capacity of the river is reduced,and the organic carbon con⁃tent increases obviously in the shallow water.In a certain range of the shallow water area,due to the gradual decline of river transport capacity,organic carbon content decreased.Using the change of sediment grain size to reflect the hydrodynamic conditions,the correlation between hydrodynamic conditions and transport organic carbon content was explored,and the changing trend of terrigenous organic carbon content was predicted.This is

关 键 词：三角洲—浅海沉积体系 分布规律 分布模式 水槽实验 陆源有机质 

分 类 号：P618.13[天文地球—矿床学]