Evaluation of Viscosity Reducers for Heavy Crude Oil Viscosity Reduction and Displacement

Abstract

Summary Chemicals for viscosity reduction play an important role in improving heavy oil production amongst other more commonly used technologies such as crude oil heating by steam, and oil dilution with solvents. The unique features of the viscosity reducer chemicals dissolved in aqueous solutions make it easy to handle and implement in wellbore lifting, huff-n-puff or well-to-well injection. In this work, the properties of water-soluble viscosity reducers were evaluated in synthetic brine for viscosity reduction of heavy crude oil. The sample with greatest performance in heavy oil viscosity reduction was selected for the heavy oil displacement test via core-flooding experiment. The efficiency of heavy oil production by the viscosity reducer injection was compared with that of polymer injection under the same experimental conditions. The cumulative heavy oil production by viscosity reducer flooding was more efficient than the polymer flooding, suggesting great potential of the viscosity reducer for heavy oil reservoir applications. Efficient viscosity reducers provide an economical way to improve heavy oil production. They would reduce the energy consumption in producing heavy oil from the subsurface formation to surface facilities. As such, the application of heavy oil viscosity reducer would not only improve well productivity but also reduce operational costs.