Evaluating Internal Corrosion Risk in VMG Gasmod


VMG Gasmod’s Pipeline Integrity Management System (PIMS) is a feature that allows the user to perform calculations for internal corrosion and evaluate the risk as it relates to their company’s internal Risk Matrix. 

Standardized reporting allows for consistent regulatory and internal submissions to be created easily. Summary and detailed reports can be generated to gain a high-level overview of the company’s risk exposure and then drill down to understand the specifics of the pipelines that need to be acted on first.

This article provides the user the steps for working with the PIMS feature. It assumes an existing VMG Gasmod case exists with a “Base Case” forecast.

1. You will need a .vts file of the Risk Matrix to import into VMG Gasmod. VMG can create one upon request. Copy the .vts file to the project directory on your C:\ drive (C:\Gasmod\”project name”\). This is the risk matrix template that will be used for the corrosion reports. This file MUST be in the project directory. 

2. In your History, select “Data-Single Point Data- Corrosion Components”. Place a check in the “CO2 and H2S” box for Gas borne species. Set the Water borne species to “Cl- and HCO3-”. 



3. Under the Risk Matrix Template, browse for the Risk Matrix .vts file you copied in Step 1. Click “Open – the file name will appear in the field. Click “OK”.


4. Select “Data- Empirical Data- PVT Properties” and in the “Fluids” window enter the desired CO2 and H2S mole fractions and Cl-, HCO3- concentrations. Click “OK”.


5. It is recommended to create a copy of your Base case named “Base-Corr” using Case- Add Case.

6. In the first timestep of the newly created case, assign the License names to the pipe by double clicking on the pipe and entering the name in the “Pipe Name” field. You can change the name of multiple pipe segments to the same License number by selecting multiple segments then right clicking and choosing “Set Pipe Name”. The License data can be acquired from regulatory or internal sources and is not required but it does add context to the reports. 



7. Click “Data- Gathering System- Pipe Segment and EQVL”, go to the “Pipe Attributes” tab. Click “Add License” and add the desired number of licenses.  Copy and Paste the license data from your source to the Pipe Attributes in VMG Gasmod, remembering to use right click - Paste    


This is just the License info used for the corrosion reports and is not used in any calculations. Click “OK”. The info on the Pipe Attributes will be tied to the pipe segment by its name (ie: License_0001).

8. Run the simulator and select the first output timestep.   


Click on a segment or select multiple segments of pipe tied to a License (License_0004), and “Select Pipes by Leg” then “Show Pipe Path Cross Section”.  


Select “Corrosion Rate” and “Likelihood” for the Y-axis. Make note of the likelihood number. The Corrosion Report and Risk Matrix buttons are now active below the plot.


9. Click on the Corrosion Report button; look at the plots. In the top right hand corner is the Risk Matrix with a Likelihood number that should match what you saw in the plot. Also note in the bottom right that the Pipe Attributes Data (License) is echoed back with some input and calculated variables.



10. Close this window and click on the Risk Matrix button to see a more detailed version. The cells in the Consequence Table shaded in light blue are the ones where the current calculation or provided information landed.



11. Perform the same inspection on the lines with other Licenses.

12. You can create a pre-populated report for internal or regulatory submission by clicking on an output timestep and then the Simulation Output button. Select the Corrosion Report tab and set the Licenses for which you want to create the report to TRUE.


13. Click the “Report Options” button and set the check boxes to match the screenshot below, then press “OK”.


14. Click “Generate Report” and fill out the Company Name in Line 1 and the Field Name in Line 2 to your desired data, click “OK”.


15. The Print screen should appear and you can select the destination to print to. In this case select your PDF generator and click “OK”.


16. Give the file a name (ie: CorrosionRept.pdf) and select where you want the file to be saved.

17. Browse to your desktop and open the file you just created. You will see the Risk Matrix Summary, a Pipeline Internal Corrosion Report Summary, and the Corrosion Report for each of the selected Pipe Licenses at the timestep you selected. Additional reports can be generated for other timesteps by selecting the appropriate timestep and repeating steps 12-17. 

The Risk Matrix Summary gives an overview of the risk exposure for all the Licenses selected.

Risk Matrix Summary


The Pipeline Internal Corrosion Report Summary is a list of the Licenses in order of risk (highest to lowest) that can be provided to staff as a “quick hit” list to address the pipe with the most risk exposure.



The Internal Corrosion Report is the same as generated on-screen and provides the details of the evaluation for the individual Licenses. 


Please contact your local VMG office for more information.

Gordon Slemko, P.Eng., VMG Calgary

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