6 replies to this topic

[sondung4ever]

My gas content: H2S 2500ppmv, 30%CO2, 10% N2 and 60% HC, Condensate gas ratio: 15bbl/mmscf.

Total production rate is 1500 mmscfd. I want to know how to chose Equation of state match with gas. Peng Robinson EOS is only for sweet gas. thanks hope someone can give me some recommendation.

[PaoloPemi]

that depends from mixture composition (i.e. condensate composition) and the list of models available in your software application,

for sizing / rating pipelines I have utilized Excel with Prode Properties as process simulation library,

with Prode you can select specific models as CPA, GERG, SAFT, Peng Robinson or Soave Redlich Kwong with complex mixing rules (Wong Sandler, or Huron Vidal) etc.

Selecting a model is not easy as every model has its limits which you should consider, but, in general, they can be more accurate than std. EOS with VDW mixing rules. (i.e. the PR or SRK packages available in most software applications).

[ankur2061]

HYSYS has a modified Peng Robinson EOS which they call Sour Peng Robinson. Similarly there is also a Sour SRK along with the SRK EOS in HYSYS.

 

If you are using PIPESIM, the Multiflash option in Compositional Model gives Peng-Robinson as the default EOS.

 

There are some papers dealing with modified EOS for evaluating sour gases and the links are provided below:

 

http://www.uic.edu/l...turalGasEOS.pdf

 

http://www.onepetro....iew?id=00074369

 

 

Regards,

Ankur.

[sondung4ever]

Thanks Paolopemi and Ankur2061. Condensate is generated from gas (non mixture). Quickly calculation I used pipesim (EOS Standard Peng-Robinson) but this is very simple study. When you design the facilities or flow assurance with olga, you need to know total liquid can receive at terminal point or at WHP, corrosion, erosion, pipeline insulation....

This gas has condensate and the liquid generation is sensitive with temperature and each EOS. Which is the best EOS match with gas

 

Thank you

[PaoloPemi]

do you have a full composition analysis ?

generic EOS models as PR or SRK with VDW mixing rules and proper BIPs may give reasonable results for hydrocarbons + CO2 and H2S when properly tuned (see the paper suggested by Ankur),

however if composition includes fluids as water etc. then things may become difficult and I would suggest to consider specific models as those mentioned above discussing PRODE PROPERTIES, see CPA, GERG, SAFT or EOS with complex mixing rules

[ankur2061]

OLGA uses its own flow correlations for hydraulic simulation of pipelines. OLGAS 2000 (2-phase) is the flow correlation developed for 2-phase by OLGA. OLGA claims it to be one of the most accurate correlations for predicting pressure drop, liquid dropout, slug formation, hydrate formation for for all kind of pipeline profiles (horizontal, vertical, inclined) for 2-phase flow which includes gas-condensate flow.

 

PIPESIM can also support OLGAS if you purchase it by paying additional money for the OLGAS flow correlation separate module.

 

Regards,

Ankur.

[RockDock]

It depends on what you want to do with it. PR will work pretty well, as long as you do not enter the liquid phase. Once you do that, you will want Electrolytic ELR for the ions that will be present, especially if you have a base present, too.