Simulations of asphalt-base crude oil flow in vertical riser

Abstract

Multiphase flow and complex flow regimes of asphalt-base crude oil with solid-state asphalt and gas presenting in submarine pipelines bring difficulty to the design and operation. For multiphase flow in risers, flow regimes are often very complex. So simulation of asphalt-base crude oil flow in vertical riser is presented using 3D Computational Fluid Dynamics and the Volume of Fluid method as a surface tracking model. Flow regimes and properties of asphalt-base crude oil were obtained, which vary depending on operating conditions, fluid properties and flow rates. Bubble flow, slug flow, wave flow, annular flow and some other flow regimes could be found in vertical riser. Different flow regime does different impact on flow properties of asphalt-base crude oil and deposition of asphalt. A deeper understanding of multiphase flow phenomena in vertical riser was obtained by the calculation results, which also provide some reference to improve the design of pipelines and assurance transportation of asphalt-base crude oil.