Liquid Drop-out in Natural Gas

[CW3]

What's an average-ballpark figure for the amount of natural gas liquids that could be produced from a gas composed of approximately 91% methane????

 

[dcasto]

TYPICALLY: zero, zilch, nada. BUT, it depends on the formation. With where you started (91% C1), I'd guess this: C2, 4%, C3 2%, iC4 .3%, C4 .6%, iC5 .15%, C5 .18%, C6+ .2%, Inerts the rest.

I've seen some resivoirs that have high methane content and a high C6+ fraction. Its the C6+ fraction that drops out.

 

[CW3]

C6+ is .22%.........approx 250MMSCFD total gas flow (800 psig/50F). Some early calcs showed in the neighborhood of 3000 bbls/day NGL's. We are trying to figure out if it should be stored in tanks and trucked to buyer, or pipelined alongside the main gas line (225 miles 24"). It's out west and winter temps get very low. We can install dew point control equipment at the station to maintain a 15F dew point once the gas leaves the station.

Thanks for replying, I see your posts all the time. Good info.

 

[dcasto]

I would estimate (GPA assumptions on C6+) that the dew point is about 50 F at 800 psig, therefore little if any liquids would drop out. If you chill the gas to 15 F, it'll make 1200 bbls/day.

If you put the 1200 bbls/day into a 210 bbl tank, you'll haul off 300 bbls/day and lose 1.5 MMSCFD in flash vapors. That would call for a stabilizer.

better yet use Silica Gel to get dew point control. and stabilize it to lose no flash gas.

 

[mbeychok]

CW3:

The title of your posting is Liquid drop-out in Natural Gas which leads one to think you are talking about drop-out in a raw natural gas pipeline.

But your posting asks ... for the amount of natural gas liquids that could be produced. If that is what you meant, then most of the ethane and all of the propane, butane, pentane and hexane+ in your gas can be recovered as NGL (natural gas liquids) by using low temperature distillation followed by conventional distillation.

This drawing may be useful to you:

Milton Beychok
(Visit me at www.air-dispersion.com)
.