原油中烷基萘的形成机理及其成熟度参数应用

THE GENERATING MECHANISM OF METHYLATED NAPHTHALENE SERIES IN CRUDE OILS AND THE APPLICATION OF THEIR MATURITY PARAMETERS

李美俊 王铁冠

Li Meijun Wang Tieguan

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. 中国石油大学资源与信息学院地化室 北京102249

Key Laboratory for Hydrocarbon Accumulation Mechanism, Ministry of Education, China University of Petroleum, Beijing 102249, China 2. Geochemical Laboratory of Resources and Information School, China University of Petroleum, Beijing 102249, China

原油和沉积有机质中烷基萘系列主要通过异构化反应和歧化反应生成,并可用芳香烃的亲电取代反应历程进行解释,所生成各种异构体的相对含量受“电子效应”和“空间效应”的控制。多甲基萘系列地球化学参数,对于原油及沉积有机质的成熟度、生物降解作用和生源组成具有表征意义。渤海湾盆地大民屯凹陷原油样品中的多甲基取代萘系列分析结果表明,在常规的甾萜类异构化作用达到平衡终点的情况下,多甲基萘取代系列地球化学参数仍能反映出大民屯凹陷高蜡油成熟度比正常油偏低,并与该区的石油地质背景和盆地模拟结果相吻合,表明多甲基萘系列相关的地球化学参数是一类非常有用的地球化学指标。

Naphthalene and methylated naphthalene series in crude oils and sedimentary organic matters are formed through isomerization and disproportionation,which can be interpreted by aromatic electrophilic substitution process.The relative concentrations of various isomers are controlled by "electronic effect" and "steric effect".Geochemical parameters related to methylated naphthalenes can be used to indicate the differences of maturity,biodegradation,and source input between oil and sedimentary organic matters.Oil samples selected from Damintun Depression in Bohai Bay Basin have been analyzed for methylated naphthalene series.The results show that the high waxy oils are more thermally mature than normal oils,even though some saturated hydrocarbon composition such as steranes and terpanes isomeric ratios get to equilibrium end.This conclusion is consistent with the geological background and the basin modeling results in the study area.It is proved that these methylated naphthalene parameters are very useful geochemical indicators.

国家自然科学基金项目(40172056)

https://doi.org/10.11781/sysydz200506606