Pipeline Drying

[Markoni]

Hello,

I am trying to correlate the time required to dry a pipe using dry air to factors such as air flow rate, air temperature, pipe length, pipe diameter etc. I know that the pipe inner wall conditions are a major factor so assume that brush pigging has already been performed and the inside is clean.

Cheers

-Marko

 

[pmover]

well, if dry air is the source medium to dry the pipe (or pipeline), then inject the dry air at one end of the pipe and measure moisture content at the vented end of the pipe (or pipeline). the time is dependent upon the amount of moisture contained in pipe (or pipeline) and the mass transfer process.

hope this helps.
good luck!
-pmover

 

[BigInch]

Assume air at 100% humidity, for which @ 70 F has 1253 lbs of water (150 gal) per 1,000,000 cubic feet. Clean with superdry air, do as Morten suggests and run a batch of MEG, or N2. Those are the 3 cheapest methods, usually in that order.Before starting ANY drying be sure to clean the line with wire brush pigs followed by soft foam pigs. Weigh pigs before and after. When they are about the same weight, you've got all the water you're going to get with the foam pigs. Then start the drying opeation.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[GregLamberson]

Markoni

pmover & BigInch are correct, you can't do it based on a calculated time. It takes some form of actually taking a reading. The time required will depend on many factors, including type of equipment used, volumes of compressors, length of pipeline, dew point requirement, etc. Vacuum drying takes longer than dry air.

As BinInch has, I have also used the old tried and true method which is to run foam pigs, weigh them before & after and when you get within a few percent, good to go. Unfortunatley you can't detemrine a dew point if that is a critical factor.

You can use menthanol as well, though dispoal may be an issue.

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[dcasto]

it's been done by BJ services already based on the 1000's of lines they have dried.

 

[BigInch]

Should we call them?

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/