东海盆地西湖凹陷轻质原油芳烃地球化学特征  

Characteristics of Aromatic Geochemistry in Light Oils from Xihu Sag in East China Sea Basin

作　　者：许婷[1,2] 侯读杰[1,2] 曹冰 陈晓东 刁慧 

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国地质大学(北京)能源学院海相储层演化与油气富集机理教育部重点实验室,北京100083 [3]中国海洋石油(中国)有限公司上海分公司,上海200030

出　　处：《沉积学报》2017年第1期182-192,共11页Acta Sedimentologica Sinica

基　　金：国家科技重大专项(2011ZX05023-001-010);国家自然科学基金(41472108)~~

摘　　要：采用GC-MS实验技术,对西湖凹陷8口井12个轻质原油样品的芳烃地球化学特征进行了系统研究。平湖斜坡带北部地区NB14-1井、NB14-2井和NB14-3井这3口井的轻质原油与平湖斜坡带中部地区的NB25-1井和NB25-2井、西次凹的HY1-1井以及黄岩构造带的HY2-1井和HY2-2井这5口井的轻质原油芳烃化合物的分布特征和相对含量存在明显差别。轻质原油芳烃馏分中以二环和三环的化合物为主,前者富含菲系列化合物,萘系列和联苯系列化合物含量相对较低,后者则相反,其富含萘系列和联苯系列化合物,菲系列化合物含量相对较低。轻质原油生源和沉积环境的研究表明,原油的母源都主要为陆源高等植物来源,成因环境都为氧化环境,但后者的1,2,5-TMN和1,2,5,6-TeMN相对含量更高,氧芴相对含量和Pr/Ph值更大,反映其母源的陆源高等植物输入程度更大,沉积环境的氧化性更强。烷基萘、烷基菲和烷基二苯并噻吩成熟度指标表明,轻质原油以达到成熟到高熟演化阶段,平湖斜坡带北部地区的NB14-1井、NB14-2井和NB14-3井这3口井的轻质原油热演化程度相对更高。Aromatic geochemical characteristics of thirteen light oil samples from nine Wells have been studied systematically by using GC-MS experimental technique. The results show that the distribution and relative content of aromatic compounds in the light oils from Well NB14-1, Well NB14-2 and well NB14-3 in the north of Pinghu slope belt are different from those of Well NB25-1 and Well NB25-2 in the middle of Pinghu slope belt, Well HY1-1 in the Xiciao, and Well HY2-1 and Well HY2-2 in Huangyan tectonic belt. The major components of aromatic fraction in light oils are bicyclic and tricyclic compounds. The light oil samples from the former wells contain more phenanthrene hydrocarbons and less naphthalene and biphenyl hydrocarbons. Meanwhile, the latter wells contain more naphthalene and biphenyl hydrocarbons and less phenanthrene hydrocarbons. The study on the source and depositional environment shows that the source material of light oils is mainly terrestrial higher plants input, and the depositional environment is oxidizing environment, but the latter wells has a higher 1,2,5-TMN and 1,2,5,6-TeMN relative content, and has a greater relative content of dibenzofuran and Pr/Ph value, reflecting that which has a greater degree of higher terrestrial plants input, with a stronger oxidative deposition environment. Alkyl-naphthalene, alkyl-phenanthrene and alkyl-dibenzothiophen are found to be optimal parameters for assessing thermal maturity characteristics, and the study shows that the light oils have reached mature-high mature oil characteristics, and the light oils in Well NB14-1, Well NB14-2 and NB14-3 have a higher maturity relatively.

关 键 词：西湖凹陷 轻质原油 芳烃 地球化学特征 原油成熟度 

分 类 号：P593[天文地球—地球化学]