Long Oil Pipeline Animation (185K)

This animation was created from a transient simulation of the start-up of a very long (~1500km) buried oil pipeline.  The pipeline had several pumping stations en route for boosting the oil pressure.

The crude oil in question had a viscosity that was a strong function of temperature and pressure at conditions close to the operating conditions.  Consequently, thermal hydraulic effects such as heat loss to the environment and transient events such as start-up were key issues for the development.

The animation shows one of the start-up procedures investigated in this study.  Initially the pipeline is at ambient temperatures, which varied as the pipeline passed through a range of environments.  As the pipeline is buried (and very long) it takes a significant period of time to reach steady state.  Liquid viscosities tend to decrease with increasing temperature.  The viscosity of this oil in particular, dropped markedly between 30 and 40°C.  Thus the gradual rise in temperature led to a gradual rise in the deliverability in the system.  However the long thermal transients, common in buried uninsulated pipelines, mean that it takes nearly a month to reach the steady state flow rate.   This study shows that sometimes even relatively simple system display interesting and surprising transient behaviour.