椒江凹陷下古新统月桂峰组半深湖--深湖相烃源岩综合识别与分布预测  

Comprehensive recognition and distribution prediction of semi-deep and deep lacustrine source rock of the Lower Paleocene Yueguifeng Formation in Jiaojiang Sag

作　　者：郭刚 廖计华 徐建永 吴斌 李林致 王欣 李峰 李婧婧 GUO Gang;LIAO Jihua;XU Jianyong;WU Bin;LI Linzhi;WANG Xin;LI Feng;LI Jingjing(CNOOC Research Institute company limited,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《海洋地质与第四纪地质》2024年第2期199-209,共11页Marine Geology & Quaternary Geology

基　　金：中海油重大科技项目“中国近海新区新领域勘探技术”(KJGG2021-0300)。

摘　　要：椒江凹陷是东海盆地已证实生烃但未获商业发现的低勘探程度区,落实其主力烃源岩层月桂峰组半深湖—深湖相烃源岩发育情况及规模是下步油气勘探亟待解决的首要问题。基于新采集的三维地震、钻井、古生物及有机地球化学数据,综合断陷作用、古地貌背景、物源区母岩岩性、有机质丰度和类型等四方面开展椒江东洼月桂峰组湖相优质烃源岩精细识别,并通过地震相类比分析,定量预测其平面分布及规模。结果表明:强烈断陷作用、适度遮挡的古地貌背景、洼陷周缘火成岩母岩区共同控制了椒江东洼月桂峰组半深湖—深湖相烃源岩的发育;其整体为好—优质烃源岩,以Ⅱ1-Ⅱ2型干酪根为主,有机质来源以低等水生生物为主且有陆生高等植物的贡献。受凹陷结构控制,椒江东洼月桂峰组半深湖—深湖相烃源岩主要发育在洼陷中心及陡坡带一侧。典型地震相表现为低频连续强振幅平行反射,基于多属性神经网络深度学习技术,预测椒江东洼月桂峰组半深湖—深湖相烃源岩最大面积为294 km^(2)、总体积为109 km^(3)。综合认为,椒江东洼具有良好的油气资源潜力与勘探前景。The Jiaojiang Sag is a low-level exploration area in the East China Sea Basin where hydrocarbon generation has been confirmed but no commercial discoveries yet have been made.Implementation of the development and scale of semi-deep lake-deep lake facies source rocks in the Yueguifeng Formation,the main source rock,is an urgent issue in the next step of oil and gas exploration.Based on the newly acquired 3D seismic,drilling,paleontological and organic geochemical data,the lake facies of the Yueguifeng Formation in the Jiaojiang Dong Subsag was developed in four aspects of rifting,paleogeomorphic background,source area parental rock lithology,and organic matter abundance and type.High-quality source rocks are precisely identified,and their planar distribution and scale are quantitatively predicted through seismic facies analogy analysis.Results show that the development of semi-deep lake to deep lake source rocks in the Yueguifeng Formation in Jiaojiang Dong Subsag is jointly controlled by strong faulting,moderately hilly palaeogeomorphic setting,and the igneous provenance area.As a whole,it is a good to excellent quality source rock,mainly composed of typeⅡ1-Ⅱ2 kerogen.The organic matter is mainly composed of lower aquatic organisms with partly contributions from higher terrestrial plants,and the typical seismic facies shows low frequency continuous strong amplitude parallel reflection.Controlled by the sag structure,the semi-deep lake to deep lake source rocks of the Yueguifeng Formation in Jiaojiang Dong Subsag are mainly developed in the central area and on one side of the steep slope belt of Jiaojiang Dong Subsag.The typical seismic phase is characterized by low-frequency continuous strong amplitude parallel reflection.Using multi-attribute neural network deeplearning technology,we predicted that the maximum area and total volume of the semi-deep lake to deep lake source rock of the Yueguifeng Formation in the subsag are 294 km^(2) and 109 km^(3),respectively.Overall,we believed that Jiaojiang Dong Subsag

关 键 词：湖相烃源岩 发育条件 分布预测 月桂峰组 椒江凹陷 东海盆地 

分 类 号：P736[天文地球—海洋地质]