Characterization of Crude Oils from Nanpu Depression by High Resolution Mass Spectrometry and Its Geochemical Significance
Wan Zhonghua
Li Sumei
Wang Zhengjun
Ren Miaosong
Zhang Hongchen
Meng Xiangbing
Sun Aiyan
Abstract：Nanpu depression is abundant in deep oil and gas resources,but the origin of the hydrocarbon is still unclear.High resolution mass spectrometry (negative-ion electrospray ionization (ESI)Fourier transform ion cyclotron resonance mass spec-trometry (FT-ICR MS))is utilized to carry out the composition and distribution of heteroatom compounds of crude oils from the Nanpu depression and its geochemical significance for the first time.The heteroatoms,N1 ,N1 O1 ,N1 O2 ,N1 O3 ,N2 ,O1 , O2 ,O3 and O4 class species,were identified by negative-ion ESI FT-ICR MS.And N1 ,O1 ,O2 class species are universal in all samples with higher relative abundance.It is found that thermal maturity obviously controls the distribution of carbon numbers and the degree of condensation of N1 and O1 class species.It is observed that parameters like C16—20/C21—50-DBE12-N1 ,C20—24/C25—50-DBE15-N1 ,DBE12/DBE9-N1 and DBE8—9/DBE4-O1 have a good correlation with Ts/Tm and TMNr.They could be used as indicators of thermal maturity of crude oils in the depression,reflecting the kinetics of thermal evolution of hydrocarbons. Significant difference was found among different layers of oils detected by negative-ion ESI FT-ICR MS,indicating that it can be applied to characterize source rocks.After a comprehensive investigation,we believe that FT-ICR MS technique is applicable in multiple geochemical aspects,such as maturity level estimation and source rock and relevant hydrocarbons determination.FT-ICR MS is significant in both the compositional characterization of the NSO compounds and the application in petroleum exploration.
Keywords：Nanpu depressioncrude oilhigh resolution mass spectrometrymaturitygeochemisitry
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 1834-1845 )