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.

In our previous articles (Energy & Fuels 2017, 31, 133−139 and Energy & Fuels 2017, 31, 8997−9005), it was presented that the asphaltenes of the Colorado field have different chemical structures, and these change the properties of crystallization of the paraffins. In this paper, we present a new way to understand the effects of the chemical structure of the asphaltenes on crude oil rheology, which includes correlating the average molecular parameters (AMPs) and the concentration of the asphaltenes with rheological properties using chemometric methods such as the partial least squares method. The asphaltenes were separated from six crude oil samples (average °API of 38) and were characterized using nuclear magnetic resonance to determine their main molecular parameters. Rheological properties including viscosity, yield stress, and gel temperature were experimentally determined for each of the crude oil samples and their respective maltenes. The results of a multivariate analysis show that the AMPs of the asphaltenes that cause the greatest effects are the ratio of peripheral aromatic carbons to aromatic carbons (C p /C ar ) and pericondensed aromatic carbons (C aaa ), which increase the gel temperature among maltenes and crude oils. The concentration of the asphaltenes (C oasf ) contributes to decreasing this property. An increase in the yield stress is mainly caused by the aliphatic chains of the asphaltenes (n) and the molecular weight (M w ), whereas C oasf causes decrease on the yield stress. Finally, the change in viscosity at 20 °C is increased by C p /C ar and is decreased by C oasf and paraffinic carbons (C s ).

The present article describes the design and construction of a device able of establishing an electrostatic field parallel to a flux of a liquid into a pipe. The generator device bases its operation on a flat parallel plate configuration under a voltage. The model E=V/d used to describe the electrostatic behavior is validated in two different ways: the first one is a lab experience and the second one through a simulation run. In the lab experience are gotten (in an indirect way) the electrostatic field magnitude and the liquid's electrical permittivity. Through the simulation run and the experimental permittivity value, is estimated, besides the intensity, the geometrical disposition of the generated field. It's validated an operation rank for the electrostatic field intensity between 0 and 1 [kV/mm]. The recommended rank for distance between the plates is from 5 to 14 [mm]. For an oil pump with a caudal between 5 and 55 [l/min], the time exposure is between 10,71 and 329,1[ms].