Effects of Asphaltene Content and Solvent Concentration on Heavy-Oil Viscosity

摘要

During a solvent-based heavy oil recovery process,significant viscosity reduction is achieved through sufficient solvent dissolution and possible asphaltene precipitation.In the second viscosity reduction mechanism,the heavy oil is in-situ upgraded as the asphaltene content in the produced heavy oil is greatly lowered.In this paper,the respective and synergistic effects of asphaltene content and solvent concentration on heavy oil viscosity are studied by measuring viscosities of heavy oil samples with different asphaltene contents and/or solvent concentrations.More specifically,a deasphalted heavy oil sample is obtained by using the standard ASTM method to extract asphaltenes from a crude heavy oil.Then reconstituted heavy oil sample is prepared by adding the extracted asphaltenes into the deasphalted heavy oil at a different asphaltene content each time and its corresponding viscosity is measured at the atmospheric pressure