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# CO2 storage in saline aquifer with ECO2N

Hello All,

I am working on CO2 storage using ECO2N.
In the output file, we have the following variables.

"P         T       SG          SS         XNACL       YH2OG       XCO2aq       PCAP       k-red"

How can I calculate the Mobile CO2, Trapped CO2 and Dissolved CO2 fractions with time? I appreciate your help. Thanking You

## 9replies

• Reservoir Engineer
• Alfredo_b
• 7 mths ago
• Reported - view

I guess you could compute for each grid element belonging to the rock domains affected by CO2 migration:

mass of dissolved CO2:   MCO2w = V  phi  (1. - SG) DL   XCO2aq

CO2 mass in the gas (NA)  phase:  MCO2g = V phi  SG   DG   YCO2g

fraction of gaseous (NA) CO2 in the mobile gas phase = (SG - SGirr)/SG

fraction of gaseous (NA) CO2 in the irreducible gas fraction (trapped?) = SGirr/SG

Regards,

Alfredo

• Luoluo
• 7 mths ago
• Reported - view

hi, I noticed that one of the values here is YCO2, and I don't see this variable inside the "flow.out" file of eco2n module. Maybe the value is 1, because the gas only needs carbon dioxide.

• Prince_Kumar.1
• 7 mths ago
• Reported - view

Thank you so much  .

• Prince_Kumar.1
• 7 mths ago
• Reported - view

Hey  , Could you please refer research paper or book from which I get expressions of these relations ? Thanking You

• Reservoir Engineer
• Alfredo_b
• 7 mths ago
• Reported - view

I would start  looking at mass balance equations for the generic component in ECO2N user's guide.

All needed parameters should be printed in the main output table, but SGirr which is known from the RELP parameters of each rock domain.

To compute needed quantities at each time step, you need a printout at each time step. In TOUGH2 you may modify the printout from sub FGTAB.

• Prince_Kumar.1
• 7 mths ago
• Reported - view

Thank You

• Prince_Kumar.1
• 7 mths ago
• Reported - view

hello,

If we want to find the above data for caprock and aquifer separately, then how to identfy the respective elemnts.?

• Alison_Alcott
• 7 mths ago
• Reported - view

If you are working in PetraSim, you can export a list of element names and materials through the File | Write Mesh data menu.

This information is also includes in the MESH file and input file, but the exported mesh data might be in a format that is easier to work with.

Also, have you looked at the mass balance reports that are included in the .out file?  These are divided into different domains (material types), but may not give you exactly what you are looking for.

• Prince_Kumar.1
• 7 mths ago
• Reported - view

Thank you so much for your support. Yes, I extracted all the required data through Matlab from the .out and mesh files. Now solving the mass of mobile/dissovle/trapped CO2 on every element at a given time step.

## Content aside

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