Oil/Gas process facility pipe sizing

[maengineering]

I have a process facility with two separators. First is a vertical 2 phase 36" x 15'. Second is a horizontal 3 phase 72" x 20'. The values from well head are 5 mmscfd, 1800 bbld water, 400 bbld oil. Design pressure is 200 psig, temp is 150 F, and ideal flow velocity is 3-4 ft/s. Working on pipe sizing and would love any tips/help on how to go about doing that. I believe the separators have 6" connections. Thanks

 

[LittleInch]

You appear to have all the information needed.

Ideal velocity, pressure, flow of liquid and gas.

Just work in units of one second.

Work out volume per second, divide by velocity and then solve for diameter.

You don't need us to do that surely?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[maengineering]

I guess my question is more so how to correctly combine the volumes of gas and fluid. Taking 2200 bbld of total fluid down to a cubic foot per second conversion gives 0.14 cu foot per second. And 5 mmscfd taken down to cu foot per second is roughly 57 cu foot per second. I know they have different densities and such. Am I missing something simple in order to combine those?

 

[LittleInch]

You haven't converted standard cubic feet to actual cubic feet.

Then you end with about 4 actual cu ft of gas per second.

Gas you can comfortably run at about 30 ft/sec.

Sizing three phase pipe is a lot more than just flow.

But if you can figure out the volume fraction of liquid and gas and then run the gas at about 10-15 ft/sec in the top part you're probably not far off.

But this is just a simple sizing to get you in the right ball park.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[horacio Torres]

You has a 2 phase flow.. On field you considered water and oil as liquid phase if the oil is a light one.

I wrote a note for 2 phase flow in LinkedIn.. Here is the link using Lockhart Martinelli equation´s

https://www.linkedin.com/pulse/two-...s-molina/?trackingId=ViYVeKu5TkWxH0y/e1n0SA==

Horacio

https://www.linkedin.com/company/lagotuy/