济阳坳陷车镇凹陷原油类型及其地球化学特征  

Types and Their Geochemical Characteristics of Crude Oil in the Chezhen Sag, Jiyang Depression

作　　者：金洪蕊 JIN Hong-rui(Research Institute of Exploration and Development,Shengli Oilfield Division,Sinopec Group,Dongying,Shandong 257015)

机构地区：[1]中国石化胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《四川地质学报》2021年第3期421-424,共4页Acta Geologica Sichuan

摘　　要：通过对济阳坳陷车镇凹陷烃源岩和原油样品进行系统的地球化学分析,认为该地区的原油主要分为四类,Ⅰ类原油来自该地区沙四段烃源岩,其γ蜡烷指数中等,重排甾烷不发育,4-甲基甾烷丰富,且具有C_(35)升藿烷"翘尾"特征,表明其母岩沉积于高盐度还原环境,这类油主要分布在大王北地区;Ⅱ类油来自沙三段烃源岩,其γ蜡烷含量较低,Pr/Ph、重排甾烷较高,且成熟度较高,母质沉积环境为淡水-微咸水、弱氧化-弱还原的沉积环境;Ⅲ类原油来自该地区沙一段烃源岩,具有高γ蜡烷含量、低4-甲基甾烷、低Pr/Ph、低成熟度的特征,其母质以低等水生生物和藻类为主,且颗石藻与硅藻类对其贡献较大,烃源岩沉积环境为半咸化还原环境;Ⅳ类原油各参数值介于Ⅱ类Ⅲ类原油之间,为沙一段和沙三段烃源岩混源供烃,该类油主要见于大王北地区。车西地区以沙三段烃源岩为主力油源。Analyses of crude oil and source rock samples show that crude oil in the Chezhen sag,Jiyang depression may be divided into 4 types.The typeⅠwas originated in the Fourth Member(Es_(4))of the Shahejie Formation and is characterized by medium gammacerane index,low diasterane,high 4-methylsterane and C35 hopane.The typeⅡwas originated in the Third Member(Es_(3))of the Shahejie Formation and is characterized by low gammacerane index,high maturity,high diasterane,indicating the source rock deposited in fresh-slightly saline water and weak redox environment.The typeⅢwas originated in the First Member(Es_(1))of the Shahejie Formation and is characterized by high gammacerane index,low maturity and high C_(28) sterane,showing the biological source mainly composed of low-grade aquatic thallophyta and algae,especially,coccolithophoridae and diatom in brackish and reducing sedimentary environment.The typeⅣis mixed oil originated from the Third Member(Es_(3))and the First Member(Es_(1))together.

关 键 词：车镇凹陷 油源 地球化学特征 沉积环境 生烃母质 

分 类 号：P618.13[天文地球—矿床学]