Molecular Characterization Of Nitrogen Compounds In Kazakstan Crude Oils

The content and distribution of nitrogen compounds are important indexes in crude oil.Because of the abundant reserves of crude oil and the rapid increase of crude oil production in Kazakhstan,it is very important to study the composition of nitrogen compounds in crude oil,which has important theoretical significance for the processing and utilization of Kazakhstan crude oil.In this paper,Gas Chromatography?GC?with Hydrogen Flameionization Detector?FID?,Gas Chromatography combined with Nitrogen Chemiluminescence Detector?NCD?and Electrospray Ionization-Fourier Transform-ion Cyclotron Resonance-mass Spectrometry?FT-ICR MS?were employed to investigate the content and distribution of nitrogen compounds in Kazakhstan crude oil.The molecular composition of nitrogen compounds in crude oil was studied.Crude oil samples from 8 oil fields in Kazakhstan:Botakhan,Uzen,Karajanbas,Zhanatalap,Village Balgimbayev,Kosshagyl,Kumkol?north?and Kumkol?south?.The molecular composition information shows that 7 of the 8crude oil samples in the Kazakhstan crude oil is the continental crude oil,and the others are the marine crude oil.The maturity of the crude oil is high,and 2 of the crude oils has been degraded by the more serious.Most of the nitrogen content of crude oil is relatively low.The relative abundance of each heteroatom type is identified as N1>O1S1>N1O1>N1O2>N1S1.The relative molecular mass distribution in the 220-620Da,the mass center of gravity in the vicinity of 400Da,the corresponding molecular carbon number distribution in C₁₅-C₆₅.The relative molecular mass distribution of non alkaline fraction is 240-620Da,the mass center of gravity is near 400Da,and the molecular weight distribution is C15-C55.The N1 class with pyrrole ring as the core,the degree of condensation distribution similar to alkaline N1,the aromatic ring number is 7 ring,with benzo carbazole and two benzo carbazole.There are 7 types of nitrogen atoms in Kazakhstan crude oil:N1,N1O1,N1O2,O1,O2,O3 and O4.N1 accounted for the absolute advantage,followed by N1O1.There are11 kinds of nitrogen containing heteroatom types which can be identified in non-alkaline fractions.N1 accounted for the absolute advantage,followed by N1O1.