Pore Space Connectivity in Different Rock-Physics Methods—Similarity and Differences
Round 1
Reviewer 1 Report
Authors investigates the connectivity by evaluating two types of carbonate rocks. Overall, this paper is great and the method is creative. However, I still have some questions. Here are my detailed comments.
(1) Describe the details of different parameters in equations. For example, what is the meaning of f in equation (4)?
(2) Pore space connectivity is more sensitive to permeability. Have you tested permeabilities of different models?
(3) Authors generated fractured rocks. Could you evaluate the fracture parameters (such as fracture length, fracture aperture, etc.) and the connectivity?
(4) Why not use the real digital rock models to verify your conclusions?
(5) In your work, how to change the pore volume fraction? Does the pore number change?
(6) There are other works about the seepage and connectivity you may need to read. For example: Li, J., Li, X., Song, M. et al. Investigating microscopic seepage characteristics and fracture effectiveness of tight sandstones: a digital core approach. Pet. Sci. (2020). https://doi.org/10.1007/s12182-020-00464-8. Yang, Y., Wang, K., Lv, Q. et al. Flow simulation considering adsorption boundary layer based on digital rock and finite element method. Pet. Sci. (2020). https://doi.org/10.1007/s12182-020-00476-4.
Author Response
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Reviewer 2 Report
This study is focused on the analysis of pore space connectivity in reservoir rocks by using five methods of rock physics. This is a very interesting study. I think it could be published with major revisions.
(1) We know that carbonate rocks, tight sandstones and shales are highly heterogeneous due to the presence of fractures. Are all models idealized? Are they comparable to actual pores and fractures?
See the following references: Pore structure and fractal characteristics of the marine shale of the Longmaxi Formation in the Changning Area, Southern Sichuan Basin, China. Front. Earth Sci. 10, 1018274. Doi: 10.3389/feart.2022.1018274
Therefore, whether this paper can consider using the actual model, such as scanning electron microscope observation photos. If not, I suggest a detailed analysis of the advantages and disadvantages of the models.
(2) The quality of Figure 4 and Figure 5 is poor. Please analyze in detail about the f-parameter vs crack density for fixed spherical porosity values.
(3) Strangely, this paper has no conclusion?
Author Response
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Reviewer 3 Report
Irina Berezina and Irina Bayuk provided an interesting study regarding pore space connectivity. The methodlogy is innnovateive and intrersint. Minor revision is suggested at this stage, and specific comments are provided below.
1. Kindly include more quantitative results in the abstract part to give authors more straightforward take-home messages.
2. Kindly include a more updated literature review in the introduction part regarding unconventional shale reservoirs like the matrix-fracture system; the article below is suggested as a starting point for the authors’ consideration. Permeability measurement of the fracture-matrix system with 3D embedded discrete fracture model. Petroleum Science2022
3. Kindly add a discussion part regarding how to validate the theoretical model using an experiment in a more general sense.
4. It looks like the authors missed the conclusion part.
Author Response
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Round 2
Reviewer 2 Report
1. Although the authors has made great efforts, I always think this model is too idealistic, even seems unscientific. I still recommend using an abstract and realistic model for analysis.
2. The quality of the figures is still poor and does not meet the requirements of publication.
3.The conclusion is too wordy.
Author Response
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