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Calculated gas pressure despite zero gas saturation

Hello TOUGH2 community,

I am running few simulations using EOS5 (water/hydrogen) with injection of hydrogen in a HLRW waste cell configuration.

I want to monitor the pressure build-up.

Despite the zero gas saturation, the code gives relatively high hydrogen pressure.

I am a little bit confused: does those values correspond to a gas pressure ?

And thank you in advance for your help.

Best regards.

 

4 replies

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    • woemn_geoscience
    • 3 mths ago
    • Reported - view

    Here's a corrected version of your text:

    ---

    Dear Haythem,

    If you are plotting the pressure from your output file `.out`, in the case where \( S_g = 0 \), it corresponds to liquid pressure. Conversely, when \( S_g > 0 \), the pressure corresponds to gas pressure.

     

    Ensure that \( S_g = 0 \) to correctly interpret this pressure as liquid pressure. However, from the image, there doesn't seem to be any stratification of liquid pressure. Have you considered a uniform liquid pressure?

    ---

    • woemn_geoscience
    • 3 mths ago
    • Reported - view

    if you want to calculate the gas pressure despite the Sg=0 you already have Xh2(hydrogen mass fraction) and you can modify your code in order to get Pg = Xh2 * H_henry +Psat

      • bahlouli_mohamed_haythem
      • 3 mths ago
      • Reported - view

      thank you very much for your answer.

      1)The absence of startification is due to zero gravity.

      2)Exactly as you wrote I am using a modified version of the code so that I get the printout of the gas pressure for any value of the saturation (even for Sg=0)

      So, my question is, physically, how can we interpret a non-zero hydrogen gas pressure calcualted using PH2 = Xh2 * H_henry despite a zero gas saturation (fully liquid saturated) ?

      (May be gas bubbles but not a free gas phase flow ?) 

      • woemn_geoscience
      • 3 mths ago
      • Reported - view

       The dissolved hydrogen Xh2creates an additional gas pressure in the fully saturated media. This is the partial gas pressure.

Content aside

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