金湖凹陷原油轻烃的地球化学特征及意义  

Geochemical Characteristics of Light Hydrocarbons in Jinhu Sag and It′s Significance

作　　者：宋宁[1] 郭海莹[1] 刘振[1] 杨帅帅[1] 

机构地区：[1]常州大学石油工程学院,江苏常州213016

出　　处：《天然气地球科学》2013年第1期123-128,共6页Natural Gas Geoscience

基　　金：常州大学引进人才基金资助

摘　　要：对金湖凹陷40个原油样品进行轻烃组分、Mango参数和成熟度等研究。甲基环己烷指数指示出该凹陷原油的干酪根类型为Ⅰ—Ⅱ型;C5轻烃特征显示有机质来源既有腐泥型也有腐殖型;Mango轻烃参数K1值基本符合轻烃稳态催化动力学轻烃成因模式,暗示着该凹陷原油有着相似的沉积环境;C5—C7轻烃三环优势大于五环和六环优势,表明该地区原油主要来源于湖相沉积环境的烃源岩;原油轻烃组分中的庚烷值和异庚烷指数都较低,原油成熟度低,原油形成温度在120～128℃之间。为进一步认识金湖凹陷原油和烃源岩的地球化学特征提供科学依据。In this paper, we measure the chemical composition of light hydrocarbons, the Mango parameters, and thermal maturity for 40 oil samples from the Jinhu sag. The methylclohexane index reveals that the oils are derived from type I and type II kerogen. The Cs light hydrocarbons indicate that the organic matter is composed of both sapropelic and humie. The Mango parameters K1 is consistent with the chemically stable structure model of light hydrocarbons,suggesting that the oils would be formed in the similar depositional environment of organic matter. Predominance of C5 to C7 tricyclic light hydrocarbon abundance is more than that of pentacyclic and hexacyclic light hydrocarbon, showing that oils are mainly originated from lacustrine source rocks. Both heptane value and isoheptane index are little,indicating the thermal maturity of oils is low. The formation temperature of oils is in range of 120-128℃. The results provide the geochemical infor- mation for further understanding of oils and source rock in the Jinhu sag.

关 键 词：金湖凹陷 原油 K1值 轻烃参数 成熟度 

分 类 号：TE122.113[石油与天然气工程—油气勘探]