Difference in Volume In Place Calculation Results between MRST and CMG

[Mukhammad Sholikhuddin]

Hello MRST users,

I am running a simple black oil simulation using MRST. For the model, I am using the example that is already available, namely blackoilTutorialSPE1.m. In addition, I also use the SPE1 dataset to build the same model in another simulator, namely CMG. All the input data has been synchronized with the dataset.

In MRST, I added some additional lines of code to calculate the volume in place values (OOIP, OGIP, OWIP). However, after I compared the results with the simulation in CMG, I found that the values are quite different.

I would like to ask, is there perhaps an error in the way I calculated or in the code I added, especially in determining the initial saturation value?

For reference, I also attached the code I used. Thank you

[wellSols, states, report] = simulateScheduleAD(state, model, schedule, 'nonlinearsolver', nls);
stateInit = states{1};

[ooip, ogip, owip] = computeOriginalInPlace(G, rock, fluid, stateInit);

[Olav Møyner]

Hi,

Aside from maybe a missing pvMult (from the fluid) I think the calculation looks correct. Maybe the units are the issue? I see that you write stb for oil etc, but MRST uses SI units. You may want to convert volumes from m^3 to the same units that you use for CMG results. Look at the functions convertTo and stb.

Olav

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Subject: [MRST Users] Difference in Volume In Place Calculation Results between MRST and CMG

 

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[Mukhammad Sholikhuddin]

Hi Olav,

I have tried your suggestion and the results are the same as CMG for OOIP and OWIP values. but why is the OGIP value different, in MRST the OGIP value still shows a value of 0. is the saturation value taken to calculate the volume in place in the last step? because in the first step saturation is still 0 for the gas [0.12, 0.88, 0]. 

Thank you

On Monday, April 14, 2025 at 4:56:57 PM UTC+7 Mukhammad Sholikhuddin wrote:

Hi Olav,

I have tried your suggestion and the results are the same as CMG for OOIP and OWIP values. but why is the OGIP value different, in MRST the OGIP value still shows a value of 0. is the saturation value taken to calculate the volume in place in the last step? because in the first step saturation is still 0 for the gas [0.12, 0.88, 0]. 

Thank you

[Olav Møyner]

Hi,

Volume in place can be calculated for any step, so it depends on your reference value.

Maybe you also need to add dissolved gas? bO.*rs.*so

Olav

Olav

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From: sinte...@googlegroups.com <sinte...@googlegroups.com> on behalf of Mukhammad Sholikhuddin <muhammadsh...@gmail.com>

Sent: Monday, April 14, 2025 12:01:48 PM

To: MRST-users: The Matlab Reservoir Simulation Toolbox User Group <sinte...@googlegroups.com>

Subject: Re: [MRST Users] Difference in Volume In Place Calculation Results between MRST and CMG

 

To view this discussion visit https://groups.google.com/d/msgid/sintef-mrst/1af35984-3c64-4a19-9475-93fb6fe9c72en%40googlegroups.com.

[Mukhammad Sholikhuddin]

Hi Olav,

Thank you so much for your suggestion! I tried the approach you recommended, and it worked perfectly. It was very helpful!