Re: Fw: Question on PhreeqcI and glycol

[navasaa@xxxxxxxxxxxxx]

Thanks you very much for the quick reply.

The water in question is a condensed water that contains up to 
approximately 1,000 chlorides and a few millimoles of both CO2 and H2S. 
It is a system that produces bas and liquid hydrocarbons.  I believe that I 
can get some of the dissociation/complexation data that I will need.

Many thanks again. Regards,

Al

----- Original Message -----
From: David L Parkhurst <dlpark@xxxxxxxx>
Date: Tuesday, July 9, 2002 7:41 pm
In-Reply-To: <001801c2272e$5708f960$763c090a@xxxxxxxxxx>
Subject: Re: Fw: Question on PhreeqcI and glycol

> 
> > Is there a way of using PhreeqcI to model the interaction of a 
> relativelylow solids brine containing both CO2 and H2S, plus some 
> glycol?  I am
> interested in modeling the behavior of such a brine vs. 
> temperature and
> pressure, to determine the extent of degradation of the glycol.
> 
> I'm not sure what you need. PHREEQC is not good with high ionic 
> strengthwaters, say 1 molal and greater. On the other hand, I'm 
> not sure what part
> of the thermodynamics you need. If it is just solubility of gases, 
> it might
> be adequate; it has a linear log activity coefficient expression for
> uncharged species. Charged species will get more unreliable the 
> higher the
> ionic strength. PHREEQC has no explicit pressure dependence in the 
> aqueousmodel, but it is possible to specify partial pressures of 
> ideal gases. I'd
> be reluctant to push things past a few atmospheres total pressure. You
> would have to define a new "Element" glycol and any
> dissociation/complexation that are pertinent. If you are trying to 
> do all
> this a priori, I suspect you can't do it. If you are trying to 
> model some
> experiments, you may be able to use some of the features of 
PHREEQC.
> 
> David
> 
> David Parkhurst (dlpark@xxxxxxxx)
> U.S. Geological Survey
> Box 25046, MS 413
> Denver Federal Center
> Denver, CO 80225
> 
> Project web page: https://wwwbrr.cr.usgs.gov/projects/GWC_coupled
> 
> 
> 
>