Calculating Gas Velocity 1

[amarks]

Hello,

Is there a quick version or rule of thumb version of calculating gas velocities in a gas well flow back line? There are so many variable, that if changed slightly can really change all of the calculations.

Just curious if someone has a quick and dirty calculation to get approximate values, making some standard assumptions, quickly without going down the rabbit hole of calculations to get very accurate results.

Would like to see what the velocity in a 3" 1502 pipe would be at various flow rates.

For example assuming:
flow rates of
45 MMSCFD
30 MMSCFD
15 MMSCFD

@ Various pressures
1500 psi
1000 psi
750 psi
500 psi

@ 80 Deg F gas temp

@ 0.7 SG of gas

@ 2.625 ID pipe

@ 80 feet long straight pipe

 

[Snickster]

Here is another gas velocity calculator which gives same results as my calc except it automatically calculates and includes the compressibility factor. You can change the default compressibility factor calculated to 1.0 by checking the adjacent box in the spreadsheet then manually typing in 1.0. Then you will get 137 ft/sec for the same input values used in my calc.

https://www.pipeeng.com/gas_velocity.html

 

[amarks]

Snickster - Thank you for working this out for me and excuse my sluggish mathematic skills. This has been super helpful. Also thank you for the online calculator link.

Pierreick - Thank you for the document giving examples and solutions, this too is very helpful.