A Study Of The Interaction Between The Oil And The Microbial And It’s Metableolites

With the development of the microbial enhanced oil recovery (MEOR), it becomes more and more important to study the components of crude oils before and after biodegradation by microbes, which can reveal effectively the interactions between crude oils and microorganisms and their metabolites. Obtained results could add our understandings of the mechanism related to the microbial enhanced oil recovery.Thin-layer chromatography/flame ionization detector (TLC/FID), chromatography,mass spectrometric (GC-MS) and fourier transform ion cyclotron resonance mass spectrometer (FI-ICRMS) were used to analyze and characterize the17samples from Henan, Daqing and Changqing oil-fields in the study. The results showed that the components of the oil samples changed after cultivated with microbes. Especially, the percentages the four fractions of the sample from Henan oil filed changed obviously; and the relative abundances of saturated hydrocarbons and asphaltene increased, on the contrary, those of aromatics and the resins decreased. The n-alkanes of all oil samples before and after the biodegradation were different, the short-chain n-alkanes in the sample of Henan oil-filed increased and the long-chain ones decreased after degradation; the n-alkanes of the C16-C26in the sample from Changqing oil-filed increased; and the C13-C20in the sample from Daqing oil-filed decreased. The series of naphthalene and philippine before and after biodegradation changed significantly. The biphenyl and the heterocyclic aromatics, especially for the dibenzothiophene in the oil from Daqing oil-filed and the dibenzofurans in the oil from Henan oil-filed, were also degraded.The results of FT-ICR MS showed that the average molecular weight of crude oil after biodegradation decreased; The major class of the compounds were N, O and O2, and there were also compounds with the class of NO, NO2, O3, O4, NS and OS etc. The class of N in all samples decreased, and the class of O2increased after the biodegradation; the compounds the class of O2contained majorly organic acids. Obtained results indicated that heteroatoms in crude oil were also degraded by microbes. The ends of long-chain heteroatoms were metabolized by microbes to organic acids that resulted in changes of compounds in the interface of oil and water, which made oil move more easily and was potential to MEOR.