Convert SCF/BBL to Metric 2

[robjul]

What is the proper conversion of SCF/BBl to metric? Cubic Feet can be converted to Cubic Meter and Barrel can also be be converted to Cubic Meter which will cancel out.

robjul

 

[MortenA]

1 SCF= 0.0268532 Nm3 (defined at 0 deg C and 1 atm)
1 BBL=0.159 m3

Best regards

Morten

 

[25362]

The use of six significant figures, instead of three, depends on the arithmetics (economics ?) in hand.

Anyway, a visit to the following threads may be tutorially apt:

thread124-166239
thread403-128474

 

[dcasto]

What the OP must be talking about is the number of standard cubic feet of gas from a bbl of that gas in its liquid form. The GPA produces these factors in both english and metric units.

 

[robjul]

Many thanks for the replies. dcasto is partly right! Am talking about the standard cubic feet of gas contained in a bbl of crude oil (not bbl of that gas in its liquid form) expressed as a single unit ratio SCF/BBL. As you can see, if I convert to metric SCF/BBL = Nm3/m3, the m3 will cancel out. And even if you show it as Nm3/m3, it looks ridiculous.

Any other unit to expressed BBL in metric aside from m3? I thought of SCF/BBL = Nm3/gal, but gal is not metric?

For example, in density conversion from English to metric, lb/ft3 = g/cc which is OK.

 

[25362]

A 65 years old conversion factor I found in my notes:

1 ft³/bbl = 1.7 x 10^-4 m³/L​

 

[25362]

To robjul,

Sorry, I should have written 1.78, not 1.7. Probably all units expressed at 60 deg F and atmospheric pressure. Anyway, the use of liter instead of cubic meter, answers your question. Right ?

 

[robjul]

Hi 25362,
I was completely surprised to realized my conversion as being 65 years old! Thanks much and yes, I better use 1 ft3/bbl = 1.78 x 10-4 m3/L.

 

[MortenA]

Im a little curious - what is the purpose of this exercise (the conversion of bbl of oil to scf gas?

SCF or Nm3 or Sm3 are just factors for number of moles of gas - so in this little exercise you convert a volume of a liquid (with a certain composition) to a number of moles? Some of the components in the oil probably count evaporate without reaching a temperature where they would ignite if oxygen was present?

Or is it a rough estimate of the volume of the associated gas or what. I have been doing process engineering for 13 years now and never came across it.

Best regards

Morten

 

[dcasto]

Well, I'm with Morten on this. The amount of gas in a bbl of oil is variable. I've seen crude with no associated gas and, pardon the lack definition because even that is variable too, the whole barrel vaporize leaving nothing. The technical term is gas oil ratio (GOR). so there isn't a definite amount of gas dissolved in a bbl of oil.

 

[ShellAnswerman]

In E&P you are talking about GOR or Gas Oil Ratio. In the U.S. is SCF/bbl (Standard cubic feet of Natural Gas per barrel of crude oil at stock tank conditions) Normally used to size your field facilities Gas Compression / Liquid Handling.
Metric Equivalent is Nm3/m3 (Normal m3 of gas per m3 oil produced) The units don't cancel..they are also refered to as cubes...so many cubes of gas produced per cube of oil.
The important thing to note is not the volume conversion, but that STP for NGPSA (14.7 psia, 60 F) is different than a metric STP (1 bar at 20 C.) So you convert the gas from British to Metric in the numerator, and the bbl of oil conversion to m3 in the denominator.

 

[25362]

IMHO, MortenA has stated the correct metric STP or NTP.

20^oC (=68^oF) & 1 atm belong, among others, to the conditions of the Compressed Gas Institute (CGI).

Anyway, as good references I recommend:

thread378-97454

http://en.wikipedia.org/wiki/Standard_temperature_and_pressure

 

[MortenA]

Doing most of my work for companies in DK/Norway i usually see two definitions:

Nm3 defined at 1 atm, 0 deg C
Sm2 defined at 1 atm, 15 deg C

That a little strange since 60 deg F is closer to 16 deg C than to 15 - but maybe somebody once tought 15 looked nicer?

I newer see 20 deg C in use - but then again pi was once defined as 4 in one us the US states so i guess anything goes.

There has been a LOT of treads on this specific subject (allthough not the core issue in this tread since its about comparing oil and gas as far as i can understand) and it just shows that you should allway somewhere just note your assumed standard conditions. If your "client" then disagrees he then has a chance to spot a potential error.

The error is about 5% on mole flow if one uses Sm3 but the reader assumes Nm3

Best regards

Morten

 

[robjul]

Hi Guys,

I was actually tasked to convert all English units to metric on a particular oil refinery project when I got caught with this Feed to a Hydrotreater column expressed in SCF/BBL. I ended up with Nm3/m3 which I had never seen before, and therefore thought it looks ridiculous as it appears to cancel out. I can't believe how a simple looking and easy unit conversion exercise had invited some degree of difficulty where I've wasted so many manhours. Thanks to ShellAnswerman for telling that the units don't really, cancel out. Many thanks too, to the other guys' contributions.