GOR adjustment in HYSYS

[silkroute]

Hi All,

Can anybody guide me in detail, how to adjust GOR (gas to oil ratio) in hysys for first stage seperator inlet stream ? Note: GOR at stock tank , inlet composition dry basis , free water at inlet is given.

silkroute.

 

[MortenA]

First of all you must know how the GOR was determined.

Usually its based on separator simulation from the reservoir simulation. The actual methode may differ from software pck to software pck e.g. a 4 stage separation. All the gas is flashed at each stage, temp determined as an adiabatic flash, the gas will not be comingled.

As is said this may differ from each type of reservoir software and the user of the reservoir simulation software. ASK! Also find out if the GOR is on dry or wet basis.

Assuming dry basis:
What i do is that i set up a similar set of separator. I would use the dry basis well fluid composition and pseudocomponents and mix the gas streams. If the GOR is different )and often you will get only one composition but a GOR that changes from year to year=, then i would take either the gas stream or the oil stream (depending on wether the OR is underdetermined or overdetermined in HYSYS) and mix this stream back into the first sep (just cheat and use a valve with a negative dP). What i would do is to use an reference stream and copy the compostion and P/T. Flow i would set manually you will need a heater in front of the first separator in order to adjust temp. The i would use an adjust to adjust the flow in the copy of the gas from the combined seps until the GOR matches. You will probably need a spreadsheet to handle the intermediate calculation.