关键词: PR状态方程, 粘度模型, 烃, 高压, 天然气, 油藏原油

Abstract: A unified viscosity model is developed to predict the viscosity of both gases and liquids simultaneously based on the similarity between P-V-T and T-μ-P,and the combination of Peng-Robinson equation of state.The features of the model is that it can describe both gases, liquids and super critical viscosity with changes of temperature,pressure,composition,as well as go through the critical point.The overall average absolute error is 7.01% when 4250 data points in total like 22 hydrocarbons,carbon dioxide and nitrogen have been calculated under broad scopes of temperature and pressure.By using the van der Waals one fluid mixing rule for the EOS parameters of mixture,the viscosity model based on two parameters Peng-Robinson EOS is utilized to predict the viscosity of mixtures.The absolute average error is 15.71% for 2441 data points concerning three binary hydrocarbon mixtures(methane/n-decane;methane/propane;methane/n-butane),while 9.8% and 13.99% for calculation values of nine natural gases and 22 reservoir crude viscosity respectively,with the calculation results superior to the existing viscosity model for oil and gas reservoir fluids.

Key words: PR equation of state, viscosity model, hydrocarbon, high pressure, natural gas, reservoir oil