Optimization of Accurate Spacing for Gas Extraction from Damaged Coal Seams Based on a Dual-Penetration Model
Round 1
Reviewer 1 Report
This article explores the technology of precise hole placement for gas production. For this purpose, industrial tests, the laws of evolution of coal dam permeability, and the double pore and double permeability model of coal are used. The authors construct a coupled permeability-strain model of a double diffusion fracture space with penetrating fractures and determine the precise placement of gas extraction holes from the reservoir using COMSOL numerical simulation software. The results of the study can be useful for the optimal organization of the placement of holes in the mines of coal deposits.
Notes:
1. Introduction section. There is no problem statement. The author needs to formulate specific goals and objectives of the study.
2. Section 2.1. it is necessary to specify what kind of coal was taken as test samples.
3. In formula 2, not all variables are disclosed. The author needs to describe all the variables used in the formulas.
4. Page 7. Text “The simulation parameters refer to some authoritative research papers [25-27].” It is necessary to supplement with a reference to the work:
Ilyushin, Y.V.; Kapostey, E.I. Developing a Comprehensive Mathematical Model for Aluminum Production in a Soderberg Electrolyser. Energies 2023, 16, 6313. https://doi.org/10.3390/en16176313
5. The work does not have a “Discussion” section. The author should add a “Discussion” section before the conclusion. In this section it is necessary to give a critical assessment of the work done. Indicate the positive and negative aspects of the study. It is also necessary to indicate the objects of industrial application of the results obtained.
6. According to the rules adopted for technical literature, the “References” section should contain 35-40 sources. The author needs to supplement the list with the works listed above, as well as other works found in search engines, for example mdpi.com. As a recommendation, I recommend looking at the following works:
Sidorenko A.A., Dmitriev P.N., Alekseev V.Yu., Sidorenko S.A. Improvement of techno-logical schemes of mining of coal seams prone to spontaneous combustion and rockbumps. Journal of Mining Institute. 2023, p. 1-13. https://doi.org/10.31897/PMI.2023.37
Marinina, O.; Nechitailo, A.; Stroykov, G.; Tsvetkova, A.; Reshneva, E.; Turovskaya, L. Technical and Economic Assessment of Energy Efficiency of Electrification of Hydrocarbon Production Facilities in Underdeveloped Areas. Sustainability 2023, 15, 9614. https://doi.org/10.3390/su15129614
Conclusion. The article needs improvement.
Author Response
Dear Reviewer:
Thank you for reviewing my manuscript in your busy schedule, I have revised the manuscript according to your comments, the revision instructions are in the annex and marked in the original text.
Best wishes,
Jin Yan
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This article develops a new coupled coal seam model and solves it by COMSOL Multiphysics. The results of the study have achieved engineering validation and are recommended for acceptance with minor modifications.
1. In the introduction, it is suggested to organize a literature review on the seepage-diffusion mechanism of coal seam gas as a way of highlighting the advantages of the dual-porosity, dual-permeability model.
2. The test section requires an explanation of the source of the coal sample data.
3. It is recommended that the combined omitted parts between equations 8, 9 and 10 be collated.
4. The units and physical quantities of some formulae in the text are missing corresponding explanations, which should be checked and added.
5. How to control the boundary conditions of a model in numerical simulation? It would be good to add relevant content.
6. In section 5, please provide more information on how the effective extent of gas extraction is determined in the field.
Author Response
Dear Reviewer:
Thank you for reviewing my manuscript in your busy schedule, I have revised the manuscript according to your comments, the revision instructions are in the annex and marked in the original text.
Best wishes,
Jin Yan
Author Response File: Author Response.pdf
Reviewer 3 Report
The author's research has certain value, but there are still several issues that need to be modified. After the modification, we will reconsider whether to accept it.
Comments for author File: Comments.pdf
Minor editing of English language required.
Author Response
Dear Reviewer:
Thank you for reviewing my manuscript in your busy schedule, I have revised the manuscript according to your comments, the revision instructions are in the annex and marked in the original text.
Best wishes,
Jin Yan
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
No comments
Reviewer 3 Report
The authors have fully addressed my comments. From my personal perspective, the results of the paper are reliable and worth publishing.
