Pipeline transportation is the most convenient means of transportation of crude oil continuously and economically from production site to refinery. However, transportation of heavy crude oil (HCO) through pipelines is difficult due to its high viscosity. The high viscosity of heavy crude oil is mainly due to the presence of poly‐aromatic compounds like resins and asphaltenes. Emulsification of HCO using surfactant is believed to be the most favorable technique to reduce the viscosity of HCO for efficient pipeline transport. In the present study, oil‐in‐water (O/W) emulsion has been formulated using a non‐ionic surfactant Polyoxyethylene (5) sorbitan monooleate (PS‐81) at different pH, surfactant concentration, and oil content. Box–Behnken response surface method has been used to optimize two responses, apparent viscosity and emulsion stability index (ESI). The optimal values of the parameters found are 75%v/v oil content, 2.5%w/v surfactant concentration, and pH value of 7 at which experimental value of emulsion viscosity is 0.2162 Pa·s, at 150 RPM, with a reduction of viscosity by 95.8% and having ESI of 98.16 after 24 h at 30°C.

Due to its high viscosity, heavy crude oil (HCO) is often transported through pipelines as concentrated oil-in-water emulsion. Here, emulsions were prepared with different concentrations of polyoxyethylene (5) sorbitan monooleate to study their flow characteristics through a horizontal pipeline. Laminar flow of HCO and an emulsion with 75 % (v/v) HCO and 25 % (v/v) water was simulated by using Ansys Fluent 2019 R3 to study the effect of temperature, volumetric flow rate, and surfactant concentration on pressure drop, dynamic viscosity, hydrodynamic entrance length, flow behavior index, consistency index, and pumping power requirement. Laminar flow of the emulsion was simulated by using a two-phase mixture flow model considering the emulsion as a pseudo-homogeneous mixture, while the flow of HCO was simulated as viscous laminar flow. Flow behavior index and consistency index were predicted from experimental viscosity data and used to predict pressure drop and, hence, the pumping power requirement.