摘要
为明确珠江口盆地顺德凹陷古近系烃源岩地球化学特征及原油来源,综合研究烃源岩总有机碳含量、岩石热解分析及烃源岩和原油生物标志物等特征,系统分析文昌组烃源岩地球化学特征,开展油源对比。结果显示:文一段和文三段烃源岩有机质丰度低,有机质类型以Ⅱ_(2)型、Ⅱ_(1)型为主,文二段有机质丰度高,有机质类型以Ⅰ型为主,整体进入成熟阶段。文昌组烃源岩整体中等Pr/Ph值,指示沉积于弱还原—弱氧化环境;低伽马蜡烷值,指示沉积于淡水环境;文一段烃源岩C_(27)—C_(28)—C_(29)规则甾烷呈反“L”型,指示陆源高等植物来源占优;而其余层位烃源岩规则甾烷主要为“V”和“L”型,指示低等水生生物与陆源高等植物的混合生源,文二段下亚段油页岩具高C304-甲基甾烷含量。恩二段原油低Pr/Ph值,低C_(19+20)TT/C_(23)TT值,C_(27)—C_(28)—C_(29)规则甾烷呈“V”型,C_(30)4-甲基甾烷丰度高。油源对比分析结果表明,恩二段原油来源于文二段下亚段油页岩。
In order to clarify the geochemical characteristics of Paleogene source rocks and the source of crude oil in Shunde Sag of Pearl River Mouth Basin,the geochemical characteristics of Wenchang Formation source rocks were analyzed systematically,followed by oil-source correlation by combining the total organic carbon content of source rocks,Rock-Eval pyrolysis and biomarkers of source rocks and crude oil.The abundance of organic matter in the E_(2)w_(1)and E_(2)w_(3)source rocks is low,and the type of organic matter is mainly typeⅡ_(2)and typeⅡ_(1).The abundance of organic matter of E_(2)w_(2)source rocks is high,and the type of organic matter is mainly type I,which enters the mature stage as a whole.The medium Pr/Ph value of the source rocks of the Wenchang Formation indicates that they were deposited in a weak reduction-weak oxidation environment,and the low gammacerane value indicates that they were deposited in a freshwater environment.The C_(27)-C_(28)-C_(29)regular steranes of the E_(2)w_(1)source rocks are anti-“L”type,indicating that the source of terrestrial higher plants is dominant,while the regular steranes of the source rocks in the other layers are mainly“V”and“L”-shaped patterns,indicating the mixed source of lower aquatic organisms and terrestrial higher plants.The oil shale of E_(2)w_(2)source rocks has high C304-methyl sterane content.E_(2)e_(2)crude oil has low Pr/Ph value,low C_(19+20)TT/C_(23)TT value,C_(27)-C_(28)-C_(29)regular steranes exhibiting a V-shaped pattern,and high abundance of C_(30)4-methyl steranes.The results of oil source comparison analysis show that the E_(2)e_(2)crude oil comes from E_(2)w_(2)source rocks.
作者
闫浩霖
庞雄奇
胡林
金秋月
郭潇潇
李悦悦
李孟辉
崔新璇
YAN Haolin;PANG Xiongqi;HU Lin;JIN Qiuyue;GUO Xiaoxiao;LI Yueyue;LI Menghui;CUI Xinxuan(Hainan Branch of China National Offshore Oil Corporation Limited,Haikou 570100,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;College of Geosciences,China University of Petroleum,Beijing 102249,China)
出处
《天然气地球科学》
北大核心
2025年第7期1367-1382,共16页
Natural Gas Geoscience
基金
中国海油(中国)有限海南分公司生产科研项目“顺德凹陷构造差异演化下成烃成藏条件分析及有利勘探方向研究”(编号:SCKY-2023-HN-3)
中国海洋石油有限公司“十四五”重大科技项目(编号:KIGG-2022-0103,KJGG2022-0404)联合资助。
关键词
顺德凹陷
烃源岩
地球化学特征
油源对比
珠江口盆地
Shunde Sag
Source rocks
Geochemical characteristics
Oil-source correlation
Pearl River Mouth Basin
作者简介
闫浩霖(1998-),男,山西长治人,硕士研究生,主要从事油气成藏机理与资源评价研究.E⁃mail:yanhlyy@163.com.
