The aim of this work was to demonstrate that the average chemical structure of the asphaltenes of a crude oil sample is unique compared with crudes of other wells from the Colorado Oil field, Colombia. Six crude oils extracted from several depths (from 2112 to 6178 ft) were studied; these crude oils have a very critical problem of deposition of paraffins and very low concentrations of asphaltenes (<1% w/w), although asphaltenes have been found with them in the organic deposits. To research this problem, first, we studied the chemical structure of asphaltenes; this information will be used in the future to understand the influence of asphaltene chemical structure on the crystallization of paraffins in waxy crude oils. The Colorado asphaltenes were characterized by nuclear magnetic resonance (NMR), mass spectrometry (MS), X-ray diffraction (XRD), and Raman spectroscopy to determine their main structural parameters. Average molecular parameters (AMPs) were analyzed using matrix plot, cluster analysis, and principal component analysis; it was demonstrated that the average molecular structures of asphaltenes differed from each other, and a cluster scatterplot suggests that there are four types of asphaltenes in the crude oils from the Colorado Oil field. The more extreme structural differences were between the asphaltenes of the crude oils obtained from the top sand and the bottom sand.
Año: 2017
ISSN: 08870624
Revista: Energy and Fuels