Experimental and Theoretical Determination of Heavy Oil Viscosity Under Reservoir Conditions

Abstract

EXPERIMENTAL AND THEORETICAL DETERMINATION OF HEAVY OIL VISCOSITY UNDER RESERVOIR CONDITIONS ABSTRACTThe USA deposits of heavy oils and tar sands contain significant energy reserves.Thermal methods, particularly steam drive and steam soak, are used to recover heavy oils and bitumen. Thermal methods rely on several displacement mechanisms to recover oil, but the most important is the reduction of crude viscosity with increasing temperature.The main objective of this research is to propose a simple procedure to predict heavy oil viscosity at reservoir conditions as a function of easily determined physical properties.This procedure will avoid costly experimental testing and reduce uncertainty in designing thermal recovery processes.First, we reviewed critically the existing literature choosing the most promising models for viscosity determination. Then, we modified an existing viscosity correlation, Pedersen et al.

Comparison of Empirical Models to Predict Viscosity of Secondary Vacuum Gas Oils

“…Semitheoretical models have a theoretical basis but include parameters that must be determined through fitting of experimental viscosity data. The semi-theoretical models are based on the principle of corresponding states and cubic equations of state [12,22,24]. They can be considered applied statistical mechanics models, such as the reaction rate theory, hard sphere theory, square well theory or their modifications [12,24].…”

“…The semi-theoretical models are based on the principle of corresponding states and cubic equations of state [12,22,24]. They can be considered applied statistical mechanics models, such as the reaction rate theory, hard sphere theory, square well theory or their modifications [12,24]. The methods of corresponding states are based on one or more reference fluids and rely on the principle that under the same reduced conditions, the same reduced viscosity is obtained for any of the fluids in a group [24].…”

“…They can be considered applied statistical mechanics models, such as the reaction rate theory, hard sphere theory, square well theory or their modifications [12,24]. The methods of corresponding states are based on one or more reference fluids and rely on the principle that under the same reduced conditions, the same reduced viscosity is obtained for any of the fluids in a group [24]. These methods predict viscosities as functions of temperature, pressure, composition, pseudo-critical properties, and the viscosity of a reference fluid at a reference temperature and pressure.…”