7 replies to this topic

[robceng]

Doe anybody have an effective method for estimating the time it takes for a pipeline cleaning pig to travel down a length (~60km, 38") of a gas pipeline?

I'm trying to put together a spreadsheet to help estimate when a gas cleaning pig will arrive in the receiver given real time flowrates, pressures, and temperatures.

Thanks for the help--

[djack77494]

The no-slip estimate would have the pig moving at the same velocity as the motive fluid. Knowing the fluid velocity (= pig velocity) and the distance to be covered, it's a simple matter to estimate the time required to cover the distance.

[JoeWong]

The no-slip estimate would have the pig moving at the same velocity as the motive fluid. Knowing the fluid velocity (= pig velocity) and the distance to be covered, it's a simple matter to estimate the time required to cover the distance.

Superficial velocity of the fluid... generally about 3-5 m/s...

[shan]

Because this is a gas line, as we all know, the compressible fluid volume will increase along the pipeline with pressure drop. Therefore, the velocity in the pipeline is not a constant value. You may have to know the inlet pressure and the outlet pressure to calculate the average gas velocity. Also, you may need considering the impact of liquid slug in the front of pig.

[shan]

Hi robceng,

You may use the following link to access the paper "Numerical Simulation of Pig Motion through Gas Pipelines" as your reference. It is NOT as simple as V=S/T.

http://espace.uq.edu..._afmc_16_07.pdf

Regards

Shan

[Fakhri]

Because this is a gas line, as we all know, the compressible fluid volume will increase along the pipeline with pressure drop. Therefore, the velocity in the pipeline is not a constant value. You may have to know the inlet pressure and the outlet pressure to calculate the average gas velocity. Also, you may need considering the impact of liquid slug in the front of pig.

Dear all,
How can we estimate the slug volume in the front of pig? Should we calculate all liquid in front of pig for all pipeline length?

Rgds,

Fachri

[VikingUK]

Doe anybody have an effective method for estimating the time it takes for a pipeline cleaning pig to travel down a length (~60km, 38") of a gas pipeline?

I'm trying to put together a spreadsheet to help estimate when a gas cleaning pig will arrive in the receiver given real time flowrates, pressures, and temperatures.

Thanks for the help--

Try this spreadsheet..you will need to add your own factors for the pig..mass, friction etc..

Attached Files

•  PIG VELOCITYideal.xls   183.5KB   957 downloads

[latexman]

Shan's link was broken. Here's a fresh link:

http://espace.librar..._afmc_16_07.pdf