Rheological law and flow characteristics of crude oil: experiment and simulation analysis

Purpose Crude oil remains a cornerstone global energy resource, and its rheological and flow characteristics are critical to the efficiency and safety of extraction and pipeline transportation. Existing studies have largely relied on empirical correlations which often fail to capture the underlying physicochemical mechanisms and significant uncertainties arise when operational conditions deviate from the original data range. The purpose of this study is to analyze the rheological and heat transfer characteristics of crude oil to solve a series of problems in engineering applications caused by its complex nature. Design/methodology/approach In this study, a combined experimental and simulation approach is well used. Rheological experiments are conducted on four African crude oil samples using an Anton Paar MCR302 rotational rheometer under different temperatures and shear rates. Three constitutive models (Power-law, Bingham and Herschel–Bulkley) are compared via R2 to determine the optimal model and parameters (K, n). The fitted results are then applied in Computational Fluid Dynamics (CFD) simulations of a horizontal straight pipe model to analyze velocity distribution, frictional resistance (f), Nusselt number (Nu) and heat transfer coefficient (h). Findings Four crude oil samples exhibit significant shear-thinning behavior and temperature dependence, belonging to pseudoplastic non-Newtonian fluids. The power-law model achieves the highest goodness of fit (R2 = 0.9). The simulation results show that the power-law index (n) has a significant impact on flow and heat transfer. As the value of n increases, both the central velocity and the friction coefficient increase, while the Nu and h exhibit a decreasing trend, confirming that the shear-thinning behavior can enhance heat transfer efficiency. Viscosity decreases with rising temperature and stabilizes at high shear rates. Research limitations/implications For experiments, this study focuses on four crude oil samples from the only African region, and lacks of study on the complexity and diversity of crude oil in other regions. In numerical simulation, this study only conducted simulation analysis on straight pipes without simulation on complex pipes. Practical implications Through a combination of experimental measurements and numerical simulations, this study effectively reveals the rheological behavior, as well as the flow and heat transfer characteristics of crude oil, which can provide a solid theoretical basis for the efficient transportation of crude oil in pipelines. Social implications Efficient transportation of crude oil is beneficial for economic stability and daily life by ensuring a reliable supply of energy and derived products. Originality/value This study combines rheological experiments with CFD simulations using directly fitted power-law parameters from real crude oil samples. It quantifies how the power-law index n affects f, Nu and h, confirming that the flow and heat transfer characteristics of crude oil can be enhanced in shear-thinning performance. The results of this study provide a theoretical basis for flow assurance of crude oil in a pipe.