Formation mechanism analysis of Sudan high acidity oils by electrospray ionization fourier transform ion cyclotron resonance mass spectrometry
应用高分辨率质谱分析苏丹高酸值原油成因

Crude oils produced from the Muglad and Melut basins, which are hydrocarbon-rich basins in Sudan, even in the Central-West African Shear Zone (CASZ), display unusually high total acid number values (TAN, up to 16 mg KOH/g oil) with high wax content and asphaltene. In order to probe the formation mechanism of Sudan high TAN oils, the authors picked up 18 oils with different TANs to analyze the composition of organic acids of crude oil by electrospray ionization fourier transform ion cyclotron resonance mass spectrometry. The research results indicated that the organic acid is consisted mainly of naphthenic acid which relative molecular weight increased gradually with the increment of biodegradation degree. The naphthenic acid of high TAN oils is consisted mainly of mono-cyclic, bi-cyclic, tri-cyclic naphthenic acid. The key reason for forming high TAN oils is only biodegradation.