Effect of Asphaltene on Phase Behavior and Thermophysical Properties of Solvent/Bitumen Systems

Abstract

Solvent-aided bitumen production from oil sands has shown promise as an alternative to thermal recovery methods. Phase behavior studies of solvent/bitumen mixtures are necessary for reservoir simulation of recovery methods, process design and operation of surface facilities, and transportation. Bitumen and heavy crudes comprise a different weight fraction of asphaltene. In this study, the effect of asphaltene on phase behavior, viscosity, and density of solvent/bitumen systems is studied. Ethane (C2H6) and carbon dioxide (CO2) are considered as solvents. Phase behavior studies and property measurements are conducted on solvent/bitumen and solvent/deasphalted bitumen systems. Solubility of C2H6 and CO2 in the original and deasphalted bitumen are measured. The viscosity and density of the liquid phase are also measured by inline viscometer and densitometer at temperature and pressure ranges of 70–130 °C and 2–8 MPa, respectively. The measured data showed that the asphaltene has no significant effect on C2H6 solubility in bitumen. However, the solubility of CO2 in the original bitumen differs from that of the deasphalted bitumen. The significant effect of asphaltene on density and viscosity of bitumen is also quantified. Mixing rules are also employed to estimate the density and viscosity of asphaltene using the density and viscosity of bitumen and deasphalted bitumen.

Characterization of deasphalted heavy fuel oil using APPI (+) FT-ICR mass spectrometry and NMR spectroscopy

“…Its kinematic viscosity is reduced by more than a factor of five after the asphaltenes are removed. The density of DAO was also lower than HFO because asphaltenes possess a higher density due to the large molecular sizes and higher aromatic content [5,64]. The DAO has a slightly lower C content and a slightly higher H content.…”

Thermophysical properties of dimethyl ether/Athabasca bitumen system

“…The schematic and details of experimental apparatus were presented in our previous work . The apparatus includes one rocking equilibrium cell, a densitometer, a viscometer, an Isco pump, a Quizix pump, one pressure indicator, one transfer cell, and a sample cell.…”

A comparative study of density estimation of asphaltene structures using group contribution methods and molecular dynamic simulations for an Australian oil field

“…Furthermore, ruthenium ion-catalyzed oxidation of the immature asphaltene was carried out to calculate the experimental data about the two different structures and densities. One of the two structures is reported to be Athabasca asphaltene (Azinfar et al 2017) and the second proposed structure is associated with asphaltene of Arab crude oil structure. The comparison of these structures with that shown in Fig.…”