Distribution of Saturates, Aromatics, Resins, and Asphaltenes Fractions in the Bituminous Layer of Athabasca Oil Sands

Abstract

The composition and distribution of saturates, aromatics, resins, and asphaltenes (SARA) fractions in the bituminous layer on the surface of Athabasca oil sands were identified using elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (SEM) with an energy-dispersive spectrometer (EDS), and Fourier transform infrared spectrometry (FTIR). The contents of elements sulfur (S) and nitrogen (N) and the ratios of carbon/ sulfur (C/S) and carbon/nitrogen (C/N) were characterized as potential indicators for evaluating the distribution of SARA fractions in the bituminous layer. Results indicated that saturates and aromatics tend to deposit at the outer bituminous layer, while asphaltenes and resins were inclined to distribute at the inner layer. Results also suggested that the distribution of SARA fractions was thermodynamically dependent and susceptible to thermal treatment. On the basis of the experimental results, a conceptual distribution model was proposed, which is supposed to serve as a basis for future studies on the liberation of bitumen from oil sands and the operation conditions for oil sands processing.

Molecular dynamic simulation of asphaltene co-aggregation with humic acid during oil spill

“…In this study, two representative asphaltene models were selected including the continental asphaltene (ASP1, C 54 H 65 NO 2 S) and the Violanthrone-79 asphaltene (ASP2, C 50 H 48 O 4 ). The selection of these two models was inspired by the facts that (i) the asphaltene samples in our laboratory experiments originated from heavy crude oil and Athabasca oil sands bitumen (Li et al, 2012a;He et al, 2013), (ii) the asphaltenes extracted from crude oil were proved to be consistent with the continental asphaltene model (Durand et al, 2008), (iii) the properties of Violanthrone-79 model were demonstrated consistent with the Athabasca bitumen asphaltene (López-Linares et al, 2006), and (iv) both models have been successfully used to simulate the asphaltene aggregation process (Ruiz-Morales and Schneider et al, 2007;Kuznicki et al, 2009). The Leonardite humic acid model (LHA, C 31 H 26 O 12 ) was used in this study (Fig.…”

Effect of solvent addition on bitumen–air bubble attachment in process water

“…Bitumen is known to be a complex mixture of natural organic molecules, containing different aliphatic, cyclic and aromatic building blocks with a number of heteroatoms (such as oxygen, sulfur and nitrogen) and heavy metals (e.g., V, Ni) (He et al, 2013;Yoon et al, 2009a;Yoon et al, 2009b). Based on the results and discussions above, the interactions between solvent-diluted bitumen and air bubbles in the process water could be described as follows.…”

Interfacial Chemistry in Steam-Based Thermal Recovery of Oil Sands Bitumen with Emphasis on Steam-Assisted Gravity Drainage and the Role of Chemical Additives

“…As far as bitumen composition is concerned, analyses based on infrared spectroscopy and elemental analysis of saturates, aromatics, resins, and asphaltenes (SARA) fractions, extracted sequentially from oil sands, suggested that these are not evenly distributed throughout the bitumen layers, with the most polar asphaltene and resin species being concentrated at the sand surfaces [11].…”