XiaoMao
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Posts posted by XiaoMao
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When I tried to run my model, I got the error message:
Time step = 0 Time (yr) = 0.000000E+00 There is a problem with fugacity coefficientI use eos2 to simulate the CO2 injection.
I set a higher partial pressure 12 for CO2 at the left bottom coner.
All other cell is zero.
I can not run my model and I have no idea how to solve this porblem.
I can not upload the sim file because it is 69KB.
the max total szie only 30KB...
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On 6/23/2020 at 5:08 PM, Alison said:
I have been experimenting with your model and converted it to EOS3 so that I could add gas saturation to the model. I was able to see the pH in the cell change by doing the following:
1. Adding the gas phase to the model. For example, initialize the model with 0.2 SG, or even just the cell with the high gas zone.
2. Under TOUGHREACT | Solution parameters, make sure that NGAS1 is checked on.
Ok
Thank you so much
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On 1/23/2020 at 10:29 AM, Alison said:
If all of these variables do not need to vary, then the "Fixed State" option would work fine. If you need to vary the temperature or pressure of the boundary, then the very large volume option (either set to geometric cells or an extra cell) would be more appropriate. This way, you could add large amounts of water or heat to the cells to force fluctuations in temperature or pressure. There is a discussion of time-varying boundaries in the PetraSim manual.
Can I use a large density , such as 1e50 kg/m3, as a constant boundary?
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My question is
Why low pH caused by carbon dioxide cannot move forward
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I downloaded the example from
https://www.thunderheadeng.com/petrasim/petrasim-4-documentation/
Example Problem 1, Linear sorption and decay (EOS9).
I want to simulate that the low pH caused by CO2 dissolution transport in the domain.
Therefore, I modified the example problem 1I set two Gas zones in the model.
CO2 partial pressure is zero in the first zone and it has been set all cells.
and then CO2 partial pressure is 10 in the second zone, and it has been set at middle one cell.
However, I got resutls like this,
low pH only occurs in the cell which is set high partial pressure and it did not move with groundwater flow.
Logically, low pH should migrate to the right. But it doesn't。
Is anyone can tell me the reason ?
you can find the sim file in the attachment.
Thank you so much.
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Thanks Alison
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In my conceptual model, geochemical reaction will produce some clay minerals, and then the clay minerals swelling will clog or block porosity in the reservoir .
so, I am not sure if Petrasim can simulate this process?
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There are three ways to set a constant boundary in Petrasim,
First, set the boundary cells to fixed state;
Second, set the boundary cells to 1E50 or more
Third, set an extra cell which has large or very large volume, and then connect the extra cell to boundary cell.
Actually, I am a beginner for Petrasim, so I am not sure whether these three ways are right.
Please let me know if I make mistake, THANKS!
My question is that there is a large lake, and my model domain is the bottom of the lake, so what type should I use when I set the top boundary?
I focus on pressure, saturation and temperature, I do not know what type boundary is more appropriately.
Thank you very much!
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On 2020/1/13 at 10:52 AM, Tom Meuzelaar said:
Hello:
You can manually titrate gases into solution using a program such as PHREEQC or The Geochemist's Workbench via reaction path model. This should calculate your dissolved concentrations.
Hope this helps,
Tom
wa, Tom
Thanks a lot
I will try to convert it by gwb.
I am doing some model by gwb..
Thansk again.
Xiao
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I exported permeability vlaues from Plot Line, they should 1E-12, 1E-13 1E-15
However, All of these are Zero.
How to solve this problem?
Permeabi. 0 0 0 0 -
54 minutes ago, Alison said:
Unfortunately, aqueous complexes were not output in TOUGHREACT v1.2, which is the version of TOUGHREACT that is packaged with PetraSim. This feature was added in later versions of TOUGHREACT. You might consider purchasing TOUGHREACT v3.3, which is available through LBL. PetraSim creates input files for TOUGHREACT v3.3. We hope to add better support with result visualization in the future.
OH, can I calculate them by myself ?
CO2, H2S and H2 consist of mixed gases. They are injected into my model.
I can get them CO2(g), H2S(g), and H2(g), so can I calculate by some method to convert them to aqueous?
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I have run my model which describes a process of injection of mixed gases.
However, I only get the results of CO2(g), H2S(g). How can I convert them form gas to aqueous? I wish I can get the result of CO2(aq) and H2S(aq).
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When I run my model, after 3.4 days, the DT is always 0.01s .
Should I wait？
Or How can I adjust model parameters?
Do you have any suggestions?
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Recently, I would like to model the Mixed gases injection process.
I have used a Extra Cell as a injection source.
However, I do not know how to determine the Air Mass Fraction.
Actually, I want to inject a hot mixed gases into a aquifer, and I have known the temperature, but I do not know the partial pressure.
Only I known is that the concentration of gas in final water, CO2 is 17mmol/kg.
So, How can I set the initial condition at the Extra Cell?
When I set the Air Mass Fraction is 0.5 or 0.55, it will stop.
The model can run if I set the Air Mass Fraction is 0.6, but it can not reach the final time I set.
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22 minutes ago, Alison said:
The SIM file you provided does not run. It says that it is missing components related to the Co2 and H2S gases. I am not able to help you set up your geochemical model. However, I do see that the initial conditions for the extra cell in your model are set to single phase with an air mass fraction of 0. This would simulate single phase water conditions. If you change the air mass fraction to 1, it will simulate single phase gas conditions. You should try changing this to 1 if you are trying to inject gas using the Extra Cell.
Yes
you are right
The model can run when I change the sg from 0 to 1.
but the DT will become 0.01 after run 10 days
do u know how to solve this problem?
by the way, can the air mass fraction be 0.5 when I want to inject mixed gases?
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u
On 2019/11/27 at 4:44 PM, Alison said:I think we would probably need to see your SIM file to comment on this. Could this have something to do with the initial phase state of the extra cell?
Could you help me to modify my model to simulate a process that can inject NaCl and hot mixed gases from Extra Cells?
Thank you very much
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On 2019/11/27 at 4:44 PM, Alison said:
I think we would probably need to see your SIM file to comment on this. Could this have something to do with the initial phase state of the extra cell?
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The results of my model show that the extra cell can inject heat, but it can not inject solute and gas.
I do not know why..
Could anyone tell me?
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According to Alison's suggestion, I used the Extra Cells to inject a mixed gases which include CO2 and H2S.
In my model, the Extra Cell was set as followed :
no sources/sinks, and the pressure was set a little bit higher than connected cell, and the density of material was set 1E99.
Gas zone: CO2=120, H2S=120
However, the results show that CO2 ranges from 9.72E-6 to 0.000913, and H2S ranges from 0 to 1.20E-24.
can anyone tell me how to get a more higher CO2 and H2S?
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12 hours ago, Alison said:
A gas injection zone option is not available in TOUGHREACT v1.2, which is the version included with PetraSim (it is included in TOUGHREACT v3.3, which is available through LBL, but it is not supported in PetraSim). One way to get around this would be to attached an "extra cell" to the injection cell, which a very large volume and a short connection distance. You can assign a gas zone to that cell that represents the gas components you want to inject into the model, and assign a higher pressure to the cell. You can find more about Extra Cells in the PetraSim manual.
Thanks
I am trying to use the EXTRA cells to implement.
I would post my results to share with you if I achieve it .
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I am trying to simulate a Hot spring system, actually it is a vapor-dominated system.
I would like to build a model that I can inject a hot mixture of gases from the bottom of model. This model is saturated cool groundwater.
And the hot gases can mix to cool groundwater, and then some chemical reaction will take place which can change the chemical composition of groundwater. The mixture of gases include CO2, water steam and H2S.
Now, I am using TOUGHREACT and EOS3. I am not sure whether it is correct.
I have built the model and used the Zone Data/Gas in TOUGHREACT, however, when I check the results, I only find gas in the injected cell, none of the other cells. I do not know why.
This is the INJECTION CELL
These are other cells：
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4 hours ago, Alison said:
I would recommend that you take a look at a steam table (assuming you are injecting water) to get an idea of enthalpy at various pressure and temperature combinations.
I am not able to post links on this website, but if you do a Google Search for "spirax sarco steam table", you should be able to get to a series of online calculators.
If you are trying to inject at a constant temperature, you should know that the enthalpy needed to maintain a specific injection temperature changes with pressure. So, it can be tricky to inject at a constant temperature in TOUGH2. One option would be to anticipate the enthalpy changes needed to maintain a temperature as pressure goes up and down (and vary it with time).
You can also assigning a very large density such as 1e40 (this gives the material a very large heat capacity). If you do this, then the fluid leaving the injection cell will always have the same temperature as the initial temperature of the injection cell.
Actually, I am trying to simulate a vapor dominated system.
I wish I can inject Steam (Temperature =250~300C, Pressure =1.5 Mpa) to my system.
In that way, I can observe the mixing process of the hot steam and cool groundwater and get the evolution of phase change.
By the way, how should I set the boundary condition if I want to inject a mixture of gases, including CO2, water steam, H2S?
Can I use the chemical zone in toughreact ?
Thank you very much!
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4 hours ago, Alison said:
I would recommend that you take a look at a steam table (assuming you are injecting water) to get an idea of enthalpy at various pressure and temperature combinations.
I am not able to post links on this website, but if you do a Google Search for "spirax sarco steam table", you should be able to get to a series of online calculators.
If you are trying to inject at a constant temperature, you should know that the enthalpy needed to maintain a specific injection temperature changes with pressure. So, it can be tricky to inject at a constant temperature in TOUGH2. One option would be to anticipate the enthalpy changes needed to maintain a temperature as pressure goes up and down (and vary it with time).
You can also assigning a very large density such as 1e40 (this gives the material a very large heat capacity). If you do this, then the fluid leaving the injection cell will always have the same temperature as the initial temperature of the injection cell.
Thank you very much!
I will try to modify the parameters according to your recommend.
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Just now, XiaoMao said:
Recently, I have build a model by tough2
I want to simulate a case that described the geothermal fluid inject to fracture rock.
The fluid temperature is about 190~280 ℃， and the rate is about 3E-5 kg/s;
How can i determine the enthalpy if I use INJECTION?
I have tried many enthalpies, some will lead to model abnormal, and some only last a low temperature.
Thanks
In addition, I wish I can know what the differences between heat in and Enthalpy
Why does my change of CO2 partial pressure have no effect on the simulation results?
in TOUGH/PetraSim forum
Posted
Hi, I am trying to simulate the weathering process by toughreact and you can find the description of my question.
I choose EOS9 because I want to know the rainwater infiltration process.
However, actually, I have no idea how to set the CO2 partial pressure.
How to keep a fixed CO2 partial pressure if I want to inject rainwater from model top?
How to set a CO2 partial pressure in the soil?
model.pptx