Oil pipelines

[kahunabean]

Can anyone tell me whether the flow along an oil pipeline is equal to to inner diameter of the pipe ? Or is it more of a river running along the bottom of the pipe ?

[rja211077]

It's highly pressurised so it very much fills the pipe

[incitatus]

flow within pipes is almost always full, as otherwise airlocks occur. incidentally even with a pressurised flow one can run gas through the pipe at the same time. This has been attempted for gas rich oil fields, but it almost always leads to grief. The aim in pieplines is to achieve a linear flow with no trubulence, such that the reynolds number is below 1000. this is why they run fast. (do you want the equations for reynolds numbers and pressure drop across a pipe?)

[cupra]

Hi incitatus - what type of pump do they use? I've done a lot of work with water, but I am intrigued - are they centrifugal (I assume that if they are, then gas would cause a problem!) and if so, are there similar caviation problems as you get with water?

[incitatus]

for oil flow mainly centrifugal. When they shift gas/liquid sols they can use hydrodynamic pressure. Cavitation occurs in all liquids and must be avoided in flammable ones if possible......

[cupra]

Cheers incitatus (although I'm an electrical enginner I like to dip my toes into other areas occaisionally!)