Scaling Tendencies for Injection Well

[Jason R]

I am trying to take a single water analysis(picture 1) run it through the software to get the following information in table form

1) Scaling Tendencies/saturation index at various temperatures and pressures(picture 2)

2) Scaling Tendencies/saturation index while varying the pH using 36% HCL(picture 3)

3) I would also like to know whether X1t or X2t can simulate actual pressures of an injection fluid, particularly for a fluid that is causing scaling in an injection well.

I am using GWB 12.

If you could point me in the right direction it would be greatly appreciated.

[Jia Wang]

Hello Jason,

Here are a few suggestions to help you get started. You would want to set up the initial system in your Basis pane. Make sure that you input your units for your components concentration correctly. The apps will allow you to enter components in elemental equivalents. You would also need to consider if any redox couples need to be disabled for your simulation. If you are starting in React, you can do a "go initial" run to check that the software is able to solve the equilibrium state of your fluid before setting up any reactions. See section 2 and 7 in the GWB Essentials User Guide for more information on configuring your calculations.

You can vary the temperature of your system within the range prescribed by your thermodynamic dataset. The log Ks in each thermodynamic dataset is compiled at a temperature and pressure stated at the top of the thermodynamic file. When you vary the temperature (e.g. via a sliding temperature path) of the system, the pressure corresponds to the temperature set. The confining pressure cannot be set independently, except in Tact and Act2. In Tact and Act2, the pressure set affects the water stability limits and the stability fields for gases, but it does not affect the equilibrium constants of minerals and other aqueous species. If pressure correction is very important, you can compile a thermo dataset at a pressure or temperature of interest. See the K2GWB, DBCreate, PyGCC references on our thermo data page for more info. To set gas pressures, you can instead set gas partial pressure or fugacity.

As for varying the pH with concentrated HCl, you would first create a 36% HCl fluid and set that as a reactant. I have described how to create this reactant in a previous post. You can titrate in various amounts until you reach the desired pH levels.

You can extract the saturation indices for various minerals by going to the plotting apps for your results. You would plot saturation indices for select minerals vs your variable of interest. Copying from Gtplot and pasting into a spreadsheet would retrieve the numerical values. For more information on this, see 8.5 exporting the plot in the GWB Essentials User Guide.

Hope this helps,
Jia Wang
Aqueous Solutions LLC