准噶尔盆地中部Ⅲ区块原油甾烷异常分布特征与成因  

Abnormal Distribution and Its Origin of Steroids in the Block Ⅲ of Central Junggar Basin

作　　者：秦黎明[1] 张枝焕[1] 杨永才[1] 李伟[2] 刘洪军[1] 梅岭[1] 

机构地区：[1]中国石油大学石油天然气成藏机理教育部重点实验室,北京102249 [2]中国石油化工股份有限公司国际勘探开发公司,北京100083

出　　处：《地球科学与环境学报》2008年第4期373-379,共7页Journal of Earth Sciences and Environment

基　　金：国家重点基础研究发展计划项目(2006CB202303)

摘　　要：对准噶尔盆地中部Ⅲ区块的3类原油或油砂样品抽提物饱和烃进行了气相色谱-质谱分析,研究了原油饱和烃中甾烷类化合物的分布特征,并对其成因做了初步探讨。结果表明:3类原油的甾烷分布特征具有一定的相似性,C27规则甾烷相对丰度明显低于C28、C29;C27、C28、C29异构体αββ型相对丰度明显高于ααα型(C28αββ(20S)或C29αββ(20R)丰度最高);但这3类原油的成因是不一致的,其影响因素主要包括热演化、生物降解、运移分馏以及古环境或岩性4个方面,其中第1、3类原油主要以热演化作用与运移作用为主,第1类原油还可能受到古环境或岩性影响,两者均不受生物降解的影响,第2类原油则受到热演化、运移作用及生物降解的共同影响。The geochemical characteristics of saturated hydrocarbons from three types of crude oils or core extracts in the block Ⅲ in central Junggar basin were investigated by gas chromatography-mass spectrometry and the distribution and origin of steroids were studied. It is found that the distribution of steroids of the three types of crude oils or core extracts are similar to each other. The relative abundance of regular steranes of C27 is lower than that of C28 and C29. It is also showed that the relative abundance of C27 , C28 and C29 of αββ-type isomers is higher than that of ααα-type （C28 of αββ- type （20S） or C29 of αββ-type （20R） is the highest）. However, the sources of three types of oils are inconsistent. The influential factors are thermal maturity, biodegradation, migrated fractionation and palaeoenvironment or lithology. The first and third types of oils are mainly affected by thermal maturity and migrated fractionation except biodegradation, and the first type of oil is possiblely influenced by palaeoenvironment or lithology. The second type of oils is mainly impacted by biodegradation beside thermal maturity and migrated fractionation.

关 键 词：原油 甾烷类化合物 分布特征 成因 准噶尔盆地 

分 类 号：P618.130.1[天文地球—矿床学]