Question

Write a brief description of Hindrance to Oil and Gas Flow in Pipelines

Answer 1

Hindrance to oil and gas flow in pipes is caused by loss in pressure head as liquid flows in pipes.

this loss in head is generally given by Darcy Waisbach equation;

h=(flv^2)/(2dg)

where h is loss in pressure head

l is length of pipe

v is velocity of pipe

d is diameter of pipe

g is accelration due to gravity

f is friction constant which basically depends on flow

Turbulent flow: loss in head due to turblunece is basicaly due to surface roughness and reynold's number.

In the case of a smooth pipe, the following equations have been developed:
equation of Blasius: f = 0.3164Re^-0.25 (Re = 3000- 100000)

equation of Nikuradse:

f=0.0032+0.221Re^-0.237

For rough pipes it is basically due to surface roughness not due to Reynolds number

Laminar Flow

if flow is laminar then f=64/Re which shows it is basically due to Reynold's number. The reason is probably that the flow turbulence caused by the wall face coarseness is limited to a region near the wall face because the velocity and therefore inertia are small, while viscous effects are large in such a laminar region.