SEPARATOR OPERATING TEMPERATURE

[Buchi]

Dear Members,

I am setting up a model on a flow station configurationg with 3 separators viz: HP, MP and Atmospheric separators.

i know that the operating pressures of each vessel is set by considering the Oil recovery and the Horsepower of the Associated Gas compressors, whichever is more conservative.

my question is what criteria should i use in fixing the operating temperatures of these vessels(excluding Atmospheric separator which is obviously ambient).

I am using PRO/II, a process simulation software.

thanks

Buchi

 

[mgp]

I'm not sure what you mean by flow station but from what I know about production separators for wellhead production fluid (which may be what you're looking at), the operating temperature in the HP separator should be that of the incoming fluid.
This must be available from the design basis for the upstream system.
There's normally no temperature regulating devices between the wellheads and the separators, except when temperatures are very high which may necessitate a wellhead cooler. You should know also if this is the case.

Regards
Mogens

 

[TD2K]

I agree with what mgp is saying for the HP separator. For the other 2 separators, fix the heat input or enthalphy input into each of them to 0 (unless you have interstage heating) and let the process simulator calculate the temperature. They will run cooler than the first separator due to the flashing off of any gases from the liquid as the pressure is reduced.

 

[MortenA]

If this is a question of normal well stream separation then then T/P of IP and MP sep shall depend on your required gas and oil spec and compressor configuration. Say that want a low RVP (Reid Vapor pressure) then maybe some heat is required "to boil of" the light components. This may on the other hand increase recycle and this is where it becomes "an art" or a least a test of "trial and error".

Set up a "base case" and study what happens when you change T and P for each stage. Important parameters are:

- Gas and oil spec (usually these MUST be met and cant be negotiated)
- Recycle stream (keep 'em small = lower compressor duty and size and smaller KO drums)
- Heat/energy consumption

Best Regards

Morten