Comparative Solution Project

We are putting the final touches to our CSP models for problems B and C. These require an augmentation to the volumes at the edge faces. The additional volume is defined thus:

"boundary volumes per unit area are specified as:

 l_B(x_B) = 5x10⁴ m for x_B on the left and right boundaries" (and also the front and back boundaries for problem C).

We read this as implying that the extra volume is 5x10⁴ m³/m² – i.e. an additional 5x10⁴ m³ is added for each 1 m² of area at the relevant face.

We have been assuming that the 5x10⁴ m³ value refers to total cell volume, rather than pore volume [where pore volume = (total volume) x (porosity)]. Is that correct?

Regards,

Hi David, 

The extra volume multiplies porosity in equation (2) and also rock volume fraction in equation (18). 

So yes, it should be interpreted as the additional cell volume, not the additional pore volume. 

Good luck with the final touches,

Jan

We are putting the final touches to our CSP models for problems B and C. These require an augmentation to the volumes at the edge faces. The additional volume is defined thus:

"boundary volumes per unit area are specified as:

 l_B(x_B) = 5x10⁴ m for x_B on the left and right boundaries" (and also the front and back boundaries for problem C).

We read this as implying that the extra volume is 5x10⁴ m³/m² – i.e. an additional 5x10⁴ m³ is added for each 1 m² of area at the relevant face.

We have been assuming that the 5x10⁴ m³ value refers to total cell volume, rather than pore volume [where pore volume = (total volume) x (porosity)]. Is that correct?

Regards,

Thanks Jan,
Can I also clarify whether the volume augmentation needs to be applied to facies 6? In the CSP definition it is stated that for problem 11B, the volume is augmented "on the left and right boundaries, within Facies 2 through 5". Facies 6 doesn't touch the left and right boundaries in 11B.
For problem 11C, the definition states, "The left, right, front, and back boundaries are defined to have boundary conditions as defined in the section 'Initial and Boundary Conditions' for the left and right boundaries." Taken literally, that would imply that only Facies 2 through 5 should be augmented. But Facies 6 does touch the front and back boundaries so I can also see that there would be a logic to providing additional boundary volume for Facies 6 too. Which approach is right?
Regards,

Hi David, 

The extra volume multiplies porosity in equation (2) and also rock volume fraction in equation (18). 

So yes, it should be interpreted as the additional cell volume, not the additional pore volume. 

Good luck with the final touches,

Jan

We are putting the final touches to our CSP models for problems B and C. These require an augmentation to the volumes at the edge faces. The additional volume is defined thus:

"boundary volumes per unit area are specified as:

 l_B(x_B) = 5x10⁴ m for x_B on the left and right boundaries" (and also the front and back boundaries for problem C).

We read this as implying that the extra volume is 5x10⁴ m³/m² – i.e. an additional 5x10⁴ m³ is added for each 1 m² of area at the relevant face.

We have been assuming that the 5x10⁴ m³ value refers to total cell volume, rather than pore volume [where pore volume = (total volume) x (porosity)]. Is that correct?

Regards,

Hi David, 

You are right that this information is omitted from the description, and thanks for brining attention to it!  I have discussed this with some colleagues, and the resolution is as follows: 

The argument for setting 0 boundary volume for Facies 1 and 7 is that these are low-permeable, and some rather unphysical (and numerical) artefacts appeared in the preliminary simulations of the early access team when these had substantial boundary volume.  This argument does not apply to Facies 6, which indeed is the most high-permeable facies. 

As such, the resolution of your question is that for 11C, the boundary volumes in contact with Facies 6 should be treated in the same manner as Facies 2-5. 

Best regards, 

Jan

Thanks Jan,
Can I also clarify whether the volume augmentation needs to be applied to facies 6? In the CSP definition it is stated that for problem 11B, the volume is augmented "on the left and right boundaries, within Facies 2 through 5". Facies 6 doesn't touch the left and right boundaries in 11B.
For problem 11C, the definition states, "The left, right, front, and back boundaries are defined to have boundary conditions as defined in the section 'Initial and Boundary Conditions' for the left and right boundaries." Taken literally, that would imply that only Facies 2 through 5 should be augmented. But Facies 6 does touch the front and back boundaries so I can also see that there would be a logic to providing additional boundary volume for Facies 6 too. Which approach is right?
Regards,

Hi David, 

The extra volume multiplies porosity in equation (2) and also rock volume fraction in equation (18). 

So yes, it should be interpreted as the additional cell volume, not the additional pore volume. 

Good luck with the final touches,

Jan

We are putting the final touches to our CSP models for problems B and C. These require an augmentation to the volumes at the edge faces. The additional volume is defined thus:

"boundary volumes per unit area are specified as:

 l_B(x_B) = 5x10⁴ m for x_B on the left and right boundaries" (and also the front and back boundaries for problem C).

We read this as implying that the extra volume is 5x10⁴ m³/m² – i.e. an additional 5x10⁴ m³ is added for each 1 m² of area at the relevant face.

We have been assuming that the 5x10⁴ m³ value refers to total cell volume, rather than pore volume [where pore volume = (total volume) x (porosity)]. Is that correct?

Regards,