Jono

Has anyone experienced a problem when adding the charge balance calculation to GSS? I receive the error message "The Parameter is Incorrect" (see attached .doc file) when trying to add the calculation for charge imbalance or charge imbalance error. The calculation methodology for charge balance error in GSS/SPEC8/REACT was questioned at the Canberra course. Correct me if I am wrong but the method that is most widely adopted is as follows: Balance error% = (cat-an)/(cat+an)*100 Is it likely that the same methodology will be employed in a patch/upgrade to GWB in the future? Cheers Jono Errro_msg_1.doc

It could be a bug, but being a complete PetraSIM novice I don't know if the way I have set the other parameters has affected the choice of EOS that I am permitted to use. I tried changing to one of the other EOS' and it seemed to work ok. My main concern is if I set up a model grid and want to change the EOS, should I be able to do so? Jono

Is it possible to change the EOS for an existing model grid? I looked at changing from EOS2 to ECO2N in the global properties dialogue box and when trying to select the ECO2N EOS it changed to the T2VOC EOS. It's a very laborious exercise having to recreate the model grid each time the same framework is to be used with a different EOS, if the EOS can't be changed.

I am having problems finding the correct layout to use in a text file to plot scatter data on Piper Durov diagrams. The manual gives examples of how to plot scatter data on bivariate plots but not trilinear diagrams. I have attempted to use calculated relative percentages in meq and the data plots, but in the wrong place on the diagrams. An example text file layout would be very useful.

Because GWB reports charge balance errors in faradays it makes it a little difficult to quantify the magnitude of error if you are used to using simple CBE percentage errors. The example I have just run gives an error of -0.0001346 faradays and a percentage error of -0.36%. Is the relationship between the two methods linear? If an analysis result returns a balance error of less than 5% it is normally considered useable, what would be the equivalent acceptable error in faradays? I know a similar question was asked early in 2008 but some clarification would be helpful. Cheers Jono

Has anyone tried to convert the GWB dbase to use the values in the SUPCRT92 slop98.dat dbase? I have found a link with scripts that claim to do this but would be interested if anybody has been successful in doing so.

Many thanks Tom. In light of your reply, we will probably run with GWB Standard and the Petrasim TOUGH2 and TOGHREACT modules to cover the supercritical reaction transport modelling. Cheers Jono

I have used GWB Essentials for low temperature modelling purposes but now need to look at deeper systems for CO2 storage simulations. For this purpose I am looking at using GWB Pro for reaction transport modelling and need to know if GWB can model reactions in the presence of supercritical CO2. I am aware of the limitations when modelling brine chemistry but my main interest is in finding out if the supercritical reaction pathways are included.