北部湾盆地迈陈凹陷徐闻1井油源研究  

Study on the Correlation Between Crude Oils and Source Rocks from Well Xuwen-1 in Maichen Sag of Beibuwan Basin

作　　者：戴祉平[1] 包建平[2] 刘玉瑞[1] 朱翠山[2] 刘宏宇[1] 

机构地区：[1]江苏油田分公司地质科学研究院,江苏扬州225009 [2]油气资源与勘探技术教育部重点实验室,长江大学地球化学系,湖北荆州434023

出　　处：《石油天然气学报》2009年第4期9-13,共5页Journal of Oil and Gas Technology

基　　金：国家"十五"重点科技攻关项目(2004BA616A02-04-01-01)

摘　　要：北部湾盆地迈陈凹陷的徐闻1井流沙港组烃源岩地球化学分析结果表明,流二段烃源岩在有机质丰度和有机质类型上均优于流三段烃源岩,显示出流二段烃源岩的生烃潜力高于流三段烃源岩。在生物标志物分布与组成特征上,流二段与流三段烃源岩呈现出藿烷系列占绝对优势、奥利烷含量中等和伽马蜡烷基本缺失的现象,表征了这套烃源岩沉积时期陆源有机质供应充分且为淡水的沉积环境。在甾烷组成特征上,流二段烃源岩C27甾烷含量较高,而流三段烃源岩中C29甾烷丰度较高,表明前者低等生物藻类的贡献大于后者。徐闻1井所产原油具有高姥植比(Pr/Ph=4.77)和基本缺乏伽马蜡烷的特点,暗示着其烃源岩形成于淡水、弱氧化-弱还原的沉积环境。油源对比的结果表明该原油的生物标志物分布与组成特征介于流二段与流三段烃源岩之间,属于典型的混源油,定量计算结果表明该原油中流二段和流三段烃源岩的贡献分别为77%和23%。Based on the analytical results of basic geochemical features on the source rocks from Oligocene Liushagang Formation from Well Xuwen-1 in MaIchen Sag of Beibuwan Basin,it was found that the abundance and the type of organic matter in the 2nd member of the source rocks in Liushagang Formaton were better than that in the 3rd member,it was implied that the hydrocarbon potential in the 2nd Member was higher than that in the 3rd Member.There was a similarity in the distribution of triterpane series of source rocks in the 2nd Member and the 3 Member,such as with dominant hopane series,moderate oleanane and almost absent gammacerane.It was indicated that those source rocks are deposited in fresh-water environment with abundant terrestrial materials input.In C27-29starane series,the relative content of C27 sterane from algae input in the source rocks of 2nd member is more that in the 3rd Member,and vice versa in C29 sterane from terrestrial matter input.For the crude oil from Well Xuwen-1,high Pr/Ph ratio and almost absent gammacerane are characterized,it shows that it is derived from the source rocks deposited under fresh-water and weakly reduced environment.By comparison,the distributions of triterpanes and steranes in the crude oils are between the source rocks of 2nd and 3rd Members,it is a typically mixed oil.Based on the quantitative analytical results of diasterane C27/C29 ratio,it is found that in this mixed oil,the contribution of the 2nd member and 3rd member 3 is about 77% and 23%,respectively.

关 键 词：烃源岩 原油 生物标志物 迈陈凹陷 北部湾盆地 

分 类 号：P618.13[天文地球—矿床学]