Motivation


One of the key challenges in Pipe Flow Dynamics is to predict the pressure distribution along the pipe during the stationary fluid transport.

In many practical cases the stationary pressure distribution can be approximated by Isothermal or Quasi-isothermal homogenous fluid flow model.

Pipeline Flow Pressure Model is addressing this problem with account of the varying pipeline trajectory, gravity effects and fluid friction with pipeline walls.


Inputs & Outputs


InputsOutputs

Intake temperature 

Pressure distribution along the pipe

Intake pressure 

Flowrate distribution along the pipe

Intake flowrate 

Flow velocity distribution along the pipe

Pipeline trajectory TVDss




Along-pipe temperature profile 







Pipe cross-section area  

Inner pipe wall roughness



Assumptions


Stationary fluid flowHomogenous fluid flowIsothermal or Quasi-isothermal conditions

Constant cross-section pipe area along hole


Equations


Pressure profilePressure gradient profileFluid velocityFluid rate


p(l) = p_s + \rho_s \, g \, z(l) - \frac{\rho_s \, q_s^2 }{2 A^2 d} \, f_s \, l



\frac{dp}{dl} = \rho_s \, g \cos \theta(l) - \frac{\rho_s \, q_s^2 }{2 A^2 d} \, f_s



q(l) =q_s = \rm const



u(l) = u_s = \frac{q_s}{A} = \rm const


where

Darcy friction factor

Reynolds number

characteristic linear dimension of the pipe

(or exactly a pipe diameter in case of a circular pipe)




Incompressible fluid  means that compressibility vanishes  and fluid velocity is going to be constant along the pipeline trajectory .

For the constant viscosity  along the pipeline trajectory the Reynolds number  and Darcy friction factor  are going to be constant along the pipeline trajectory.

Equation  becomes:

\frac{dp}{dl} = \rho_s \, g \, \frac{dz}{dl}  - \frac{\rho_s \, q_s^2 }{2 A^2 d} f_s

which leads to  after substituting   and can be explicitly integrated leading to .



The first term in the right side of  defines the hydrostatic column of static fluid while the last term defines the friction losses under fluid movement:


In most practical applications in water producing or water injecting wells, water can be considered as incompressible and friction factor  can be assumed constant  along-hole ( see  Darcy friction factor in water producing/injecting wells ).



See also


Physics / Fluid Dynamics / Pipe Flow Dynamics / Pipe Flow Simulation / Pressure Profile in Stationary Quasi-Isothermal Homogenous Pipe Flow @model

Darcy friction factor ] [ Darcy friction factor @model ] 

Homogenous Pipe Flow Temperature Profile @model ]



References




PipeFlowSimulator.xls
Pressure loss in pipe @ neutrium.net 
R. Shankar, Pipe Flow Calculations, Clarkson University [PDF]
Pressure loss in chokes @ Studopedia