Accurate prediction of the viscosity of light crude oils using one-parameter friction theory: Effect of crude oil characterization methods and property correlations

Viscosity Modeling of Light Crude Oils under Gas Injection Using One-Parameter Friction Theory

“…This section provides a brief review of the models used in this work. These same concepts were implemented in our previous work . First, an overview of the three characterization methods with techniques to assign the pseudo-component EoS parameters for modeling phase behavior is provided.…”

“…Since experimentally measuring viscosity over a wide range of conditions is expensive and time-consuming, predictive models built on theoretical, empirical, or semitheoretical bases are commonly used for estimating viscosity. Multiple review articles comparing the performance of these models are available in the literature. − Semitheoretical models such as friction theory, expanded fluid theory, and the corresponding states methods − have found immense popularity in industrial applications because they are generally not restricted to only one phase or limited ranges of temperatures, pressures, and compositions unlike empirical models. − Semi-theoretical models have been extensively used to predict the viscosity of crude oils. ,− …”

“…One-parameter friction theory is one of the more popular versions of the model that uses a cubic EoS such as the Peng–Robinson (PR) EoS to obtain pressure and has been shown to predict the viscosity of pure components with high accuracy. Referred to as PR FT, this framework has been proven successful in modeling viscosity of simple n -alkane mixtures, , natural gas, hythane, light crude oils, − , and heavy crude oils. − …”

“…To model the viscosity of crude oils, friction theory requires the compositional breakdown as input and it is, therefore, paired with a characterization method to accurately capture phase behavior. It has been previously established that the choice of characterization method has a direct impact on the accuracy of PR FT viscosity predictions. , Various characterization methods have been combined with PR FT to model the viscosity of live crude oils including the Single Carbon Number (SCN) method for the cubic EoS, , the Chi-Square (CS) method, the SARA-based method for the PC-SAFT EoS (SAFT-SARA), the SARA-based method for the PR EoS (PR-SARA), the Single Liquid Fraction method for the PC-SAFT EoS (SAFT-SLF), and the single liquid fraction method for the PR EoS (PR-SLF). , Khemka et al formulated multiple PR FT frameworks for modeling the high-temperature, high-pressure viscosity of live crude oils using the PR-SARA and SCN characterization methods and compared their performances to a modification of the previously proposed SAFT-SARA framework . When SARA analysis was unavailable for any crude, the SLF characterization was used.…”

“…Viscosity under gas injection is a key property in multiple areas of interest: (1) reservoir simulation to study the flow of hydrocarbons during enhanced oil recovery studies with gas injection, (2) accurate multiphase flow behavior modeling in production tubing to analyze well performance during gas lift, and (3) modeling the transport of precipitated asphaltene particles and subsequent deposition in the production tubing during gas lift which is a major flow assurance problem. − Given its importance for practical applications, the purpose of this study is to address the current lack of methods for viscosity modeling of crude oils under gas injection. In this work, the predictive capabilities of the three PR FT methodologies proposed by Khemka et al are further explored to model the viscosity of light crude oil blends with gas injection and compare the accuracy of predictions. The SARA-based methods have proven effective in modeling the phase behavior and asphaltene onset pressure under gas injection, , and investigating their capability to model viscosity under gas injection is of significant importance to the oil industry.…”