Characterization of petroleum acids using combined FT-IR, FT-ICR-MS and GC-MS: Implications for the origin of high acidity oils in the Muglad Basin, Sudan

Examination of whole oils and Isolated oil acidic fractions using Fourier transform Infrared (FT-IR), negative-ion microelectrospray high-field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and gas chromatography-mass spectrometry (GC-MS) reveals significant differences in the functional groups, chemical classes and molecular weights of acidic components in crude oils derived from inland lacustrine source rocks in the Fula Sub-basin. Muglad Basin. Sudan Correlation of the total acid number value (TAN) and bulk and molecular compositions with reservoir depth (temperature) indicates a strong influence of biodegradation on the origin of the high acidity in the oils and the possibility of distinguishing acidic compounds newly formed by way of in-reservoir biodegradation and those contributed directly from oil degrading bacteria Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.