The Formation And Distribution Of Maleimides In Petroleum

Maleimides are degradation products or derivatives of chlorophyll in polar components of sediments,rocks,soil,and crude oil,and are expected to be a novel kind of non-hydrocarbon biomarkers.In order to explore the geochemical information contained,21 rock samples from the K₂qn¹ and K₂n¹ layers in Songliao Basin and 6 crude oil samples from the Pearl River Mouth Basin were collected in this thesis and maleimides components were successfully separated from them.And analyzed the maleimides in these samples by gas chromatography-mass spectrometry(GC-MS)and full two-dimensional gas chromatography-time of flight mass spectrometry(GCGC-To FMS),combined with the mixed sample and literature compared to samples of maleimides were analyzed and identified.Abundant maleimide compounds were detected in rock samples from Songliao Basin and crude oil samples from the Pearl River Mouth Basin,of which three maleimides series were detected in the rock samples,including methyl and Alkyl substituted maleimides series,ethyl and alkyl substituted maleimides series,and phenyl substituted maleimides series,of which phenyl substituted maleimides series dominate.Abundant Me,i-Bu maleimide and Me,n-Pr maleimide were detected in rock samples from the K₂qn¹ and K₂n¹ rocks in Songliao Basin,which were derived from the bacteriochlorophylls of green phototrophic sulfur bacteria,whose presence indicates photic zone euxinia.This H₂S-rich,light-transmitting water environment is valid evidence of two whole basin hypoxic events in the Late Cretaceous of Songliao Basin.In addition,Me,i-Bu/Me,Et and Me,n-Pr/Me,Et can be used as new parameters for judging the source rock depositional environment and redox conditions,and total phenyl series/total maleimides can be used as a new parameter for evaluating maturity and has a good application prospect in hydrocarbon geochemistry.In the crude oil of Pearl River Mouth Basin,maleimide shows the distribution characteristics of methyl and alkyl substituted maleimide series and phenyl substituted maleimide series.Among them,Methyl,ethyl-maleimide(Me,Et-maleimide)dominates.The water-washing effect can consume maleimide compounds in the crude oil hydrocarbons of the Pearl River Mouth Basin,while degradation of microorganisms of grade 5 and below has no obvious change on the content of maleimide series.The crude oil in the Pearl River Mouth Basin mainly includes methyl and alkyl-substituted maleimide series and phenyl-substituted maleimide series,in which the methyl,ethyl-maleimide derived from chlorophyll dominates.Maleimides have strong resistance to biodegradation,and the effect of water washing leads to a decrease in the content of maleimides in crude oil.