Title

GEOCHEMICAL CHARACTERISTICS OF THE CRUDE OIL IN THE LUXI SAG, THE KAILU BASIN

作者

周树青黄海平刘玉明

Authors

Zhou Shuqing Huang Haiping Liu Yuming

单位

中国地质大学能源学院, 北京 100083

Organization

School of Energy Resources, Chinese University of Geosciences, Beijing 100083, China

摘要

开鲁盆地陆西凹陷是辽河外围盆地中勘探程度最高、发现油藏最多的地区。通过原油样品的精细地球化学分析,研究了陆西凹陷包1块和包14块原油的成熟度、生源输入和沉积环境特征。陆西凹陷包1块和包14块原油具有相似的地球化学特征:Pr/Ph小于0.6;甾烷分布以C29甾烷为主;三环萜明显小于五环萜,三环萜/五环萜比值小于0.15,三环萜以C23为基峰,五环萜以C30为基峰,Ts/Tm在0.7~1.0左右,含有一定量的γ蜡烷。但二者也有一定差异,包14块成熟度略高;正构烷烃分布包1块多以C20为基峰,包14块多以C21为基峰;包1块C15-21/C22-28比值比包14块高;包1块具有较高的γ蜡烷指数,指示沉积时较强的盐度环境;包1块藿烷/甾烷比值较低,可能反映藻类比较发育和高盐度对细菌的抑制作用。

Abstract

The Luxi Sag is the area which has the highest exploration degree and the most oil and gas discoveries among the peripheral basins of Liaohe Basin.The crude oil maturity,the organic matter input and the depositional environment of Bao 1 Block and Bao 14 Block in the Luxi Sag have been studied based on the precise geochemical analysises of the crude oil samples.Many similar geochemical characteristics between the crude oils from Bao 1 Block and Bao 14 Block have been found,in Cluding:the Pr/Ph ratio is less than 0.6;the regular sterane distribution is dominated by C29-steranes;the tricy Clic/pentacy Clic terpane ratio is less than 0.15,with the content of tricy Clic terpane being obviously less than pentacy Clic terpane;the base peak of the tricy Clic terpane is C23 and that of the pentacy Clic terpanes is C30,with the Ts/Tm ratio ranging from 0.7 to 1.0 and certain amount of gamacerene.But some differences between the two blocks also exist.Bao 14 Block has a slightly higher maturity,the base peak of n-alkanes in Bao 1 Block is mostly characterized by C20,and that in Bao 14 Block is mostly characterized by C21;the ratio of C15-21/C22-28 in Bao 1 Block is higher than that in Bao 14 Block;and Bao 1 Block has higher gamacerene index,indicating that Bao 1 Block was deposited under a higher salinity environment.The hopane/sterane ratio in Bao 1 Block is lower,suggesting that the algae were rather developed and the higher salinity environment may suppress the bateria.

关键词：

生物标志物; 原油; 地球化学特征; 生源输入; 沉积环境; 陆西凹陷; 开鲁盆地;

Keywords:

biomarker; crude oil; geochemical characteristics; organic matter input; depositional environment; the Luxi Sag; the Kailu Basin;

基金项目

教育部科学技术研究重点项目(106112)

DOI

https://doi.org/10.11781/sysydz200706598

开鲁盆地陆西凹陷原油地球化学特征