Heavy Oil Viscosity Prediction Model Research

The data of viscosity of heavy oil is base on oil and gas reservoir numerical simulation. Although the viscosity is able to measure from experiment, it is time-consuming and labor-intensive, and higher cost compared to model calculations. Then, it is important to develop new oil and gas viscosity model.When existing viscosity model applied to predict viscosity of heavy oil formation, because of h high contents of heavy constituents and resin-asphaltenes, it is much large error of calculating viscosity which following to use the measured parameters to characterization the heavy component. This paper is base on much more investigation, and chooses common viscosity model which based on the PR equation of state of well application effect in current to as improve objective. There are two improve methods of the original model of the process on characteristics of the heavy constituents. The one improve the PR viscosity model that applies to the process on characteristics of a single heavy pseudo-component of a little heavy oil with simple and easy to do, the other is that applies to the process on characteristics of the double heavy pseudo-component of much heavy oil with contents of resin-asphaltenes.Main contents and results:(1) carried out experiments of heavy oil samples, Including the basic properties, viscosity-temperature curve and the viscosity-pressure curve, et al of the ground degassed oil and oil in original place under atmospheric pressure and high pressure, and obtain a number of59viscosity data.(2) Starting from the viscosity of factors, there can get density and relative molecular weight. The similar normal boiling point of pure substance, the maximum value of those viscosity can be a minimum of1.34,1.31and2.08times. For heavy oil mixtures, similar density, but two species of heavy oil mixture samples with different contents of resin and asphaltene have different viscosity. For example, the Tuha sample is6.14times the viscosity of sample A in Syria. So, for heavy oil with high contents of resin and asphaltene, the viscosity of calculation error which using the measured physical parameters to characterize the heavy hydrocarbon fractionation often become larger.(3) Established a method of characteristics the PR viscosity model, and characteristics the heavy pseudo-component which verify the model of the process on characteristics of a single heavy pseudo-component. Moreover, calculated the physical parameters of the heavy hydrocarbon components of40single carbon number, and established the associated method of applying to the improved model of the characteristics of the heavy fractionation. This model for the heavy oil sample system have the maximum relative error of9.81%, the minimum relative error of5.0%and average error of7.41%.(4) Established and verified a model of characteristics of the double heavy pseudo-component. This model is utilized the weight percent of resin and asphaltene to make improve the original viscosity model characterize of heavy oil heavy pseudo-component and get. This model for the heavy oil sample system have the maximum relative error of4.1%, the minimum relative error of2.75%and average error of3.43%.(5) Compared and analysis the three models of the average relative error of the viscosity of heavy oil samples. It can be seen that the improved model is significantly more accurate than the original model.