Converting Feet Gas Column
Converting Feet Gas Column
(OP)
I recieved an old document with pressure listed in "Feet Gas Column". Does anyone know what this is or how to convert it to inches water column?
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
Converting Feet Gas Column
|
RE: Converting Feet Gas Column
The equation used most often in Oil & Gas for figuring bottom-hole pressure with a gas column is:
P(bottom) = P(top)* exp((0.01875*SG*depth)/T/Z)
With:
Pressure in psia
Temperature in Rankine
SG relative to air
depth is column height in feet
[Note: since atmospheric pressure is a significant number of feet of gas column it is important to get it right at the top. Predicting gauge pressure at the bottom is a really tricky thing since on well-magnitude problems your elevation can be thousands of ft lower than surface pressure, for a monometer problem this shouldn't be a problem]
The result is in psia and can be converted to ft of pure water at 60F by dividing the answer by 0.433 psi/ft.
This equation tracks well on wellbore-magnitude problems (i.e. hundreds of feet), I'm not sure how well it would work on monometer-magnitude problems.
David Simpson, PE
MuleShoe Engineering
www.muleshoe-eng.com
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
The harder I work, the luckier I seem
RE: Converting Feet Gas Column
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com
RE: Converting Feet Gas Column
David
RE: Converting Feet Gas Column
BigInch
-born in the trenches.
http://virtualpipeline.spaces.msn.com