地质学报2025，Vol.99Issue(5)：1676-1689,14.DOI:10.19762/j.cnki.dizhixuebao.2024118
生物降解作用对原油中长链烷基萘系列分布与组成的影响
Effects of biodegradation on distributions and compositions of long-chain n-alkylnaphthalene series in the crude oils
摘要
Abstract
This study analyzed the saturated and aromatic hydrocarbon fractions of two crude oil types from the Huangjue oilfield(Gaoyou sag)and the Wanglongzhuang oilfield(Jinhu sag)in the Subei basin using gas chromatography-mass spectrometry.We compared the distributions and compositions of long-chain n-alkylnaphthalene series and discussed the effects of biodegradation on these compounds in the different crude oils.Analysis of chain alkanes,including normal alkanes and phytane series,indicated slight biodegradation(levels 1～2 on the Peters and Moldowan(PM)scale)in some Wanglongzhuang oilfield samples.In contrast,some Huangjue oilfield samples exhibited slight to moderate biodegradation(levels 1～3 on the PM scale).Both 2-alkyl and 1-alkyl n-alkylnaphthalene series were detected in the aromatic hydrocarbon fractions of crude oils from both oilfields,with side chain carbon numbers ranging from C1 to nC26.While C0-4 alkylnaphthalenes were dominant,the abundances of nC5-26 alkylnaphthalene were relatively low.In unbiodegraded oils,the n-alkylnaphthalene series displayed a bimodal distribution without a clear predominance of odd or even carbon numbers.The relative abundance of 2-alkylnaphthalenes slightly exceeded that of 1-alkylnaphthalenes,with 2-alkyl-N/1-alkyl-N ratios ranging from 1.0 to 1.5,suggesting a similar biological origin.Slightly biodegraded(levels 1～2)oils showed complete n-alkylnaphthalene series,but with reduced relative abundance of nC11-26 alkylnaphthalenes,weakening the bimodal pattern.In addition,1-alkylnaphthalene abundances decreased,and 2-alkyl-N/1-alkyl-N ratios increased significantly compared to unbiodegraded oils,suggesting that n-alkylnaphthalenes are susceptible to biodegradation,similar to normal alkanes,with 1-alkylnaphthalenes being more vulnerable than 2-alkylnaphthalenes.In moderately biodegraded(level 3)oils,two series of n-alkylnaphthalenes became incomplete.nC4-10 2-alkylnaphthalenes dominanted,while nC11-26 1-alkylnaphthalenses nearly disappeared.The 2-alkyl-N/1-alkyl-N ratios increased rapidly and became irregular compared to unbiodegraded and slightly biodegraded oils.These findings suggest that n-alkylnaphthalenes exhibit biodegradation resistance similar to normal alkanes in the crude oils.However,unlike normal alkanes,higher molecular weight n-alkylnaphthalenes are more easily biodegraded than lower molecular weight components.Furthermore,1-alkylnaphthalenes are more susceptible to biodegradation than 2-alkylnaphthalenes,the variation of their ratios reflects the extent of biodegradation.关键词
长链烷基萘系列/2-烷基萘/1-烷基萘/生物降解作用/原油/苏北盆地Key words
long-chain n-alkylnaphthalene series/2-alkylnaphthalenes/1-alkylnaphthalenes/biodegradation/crude oils/Subei basin引用本文复制引用
包建平,朱翠山..生物降解作用对原油中长链烷基萘系列分布与组成的影响[J].地质学报,2025,99(5):1676-1689,14.基金项目
本文为国家自然科学基金项目(编号41772119)资助的成果. （编号41772119）
