Construction Method of Honeycomb Gas Flow Network Channel: Structure-Based and Engineering Response on Plastic Zone Distribution Form
Round 1
Reviewer 1 Report
The manuscript derived the implicit equation for the plastic zone boundary of the borehole’s surrounding rock, analyzed the influence of bidirectional confining pressure ratio, coal body strength, gas pressure and aperture on the distribution of surrounding rock plastic zone and permeability-increasing circle, constructed a honeycomb gas flow network channel structure based on the distribution of plastic zones, realize the connection of the coal seam gas flow and enrichment area, and improve the gas drainage rate.
It is recommended that major revisions be made before it is accepted.
1. The abstract and conclusions of this manuscript need further refinement and improvement, and the English language should be improved throughout the manuscript. Please further sort out the full text to enhance the readability.
2. What’s the difference between the three models in Figure 4? Rmax in butterfly model is multi times of the borehole, is it correct?
3. The borehole numbers are too many in Figures 14 and 15, which conditions may apply such model?
4. More details needed in the Engineering test part, include the field application process, the monitoring parameters, and the field test effect, etc.
Author Response
REPLIES TO REVIEWERS’ COMMENTS
Dear Professor,
We thank you and the reviewers for considering our manuscript. Their comments have helped us revise and improve our manuscript. We have studied all comments and made the corresponding corrections. The language of the manuscript has also been improved. I hope it meets with your approval. All changes are indicated in red, and the response to each comment is provided below:
We thank you for the opportunity to resubmit our manuscript.
Sincerely yours,
Chao Yuan
Replies to Reviewer #1:
- The abstract and conclusions of this manuscript need further refinement and improvement, and the English language should be improved throughout the manuscript. Please further sort out the full text to enhance the readability.
We have further improved and simplified the abstract and conclusion parts of the manuscript, focusing on the innovation and main research results of the manuscript. At the same time, we also modified the English expression of the manuscript.
- What’s the difference between the three models in Figure 4? Rmaxin butterfly model is multi times of the borehole, is it correct?
The three models are the distribution pattern of plastic zone of borehole surrounding rock under different two-way confining pressure ratios. That is, under the condition that other influencing factors remain unchanged, different two-way confining pressure ratios determine the distribution pattern of plastic zone of borehole surrounding rock. When the two-way confining pressure ratio is 1, the plastic zone presents a circular distribution pattern. When the two-way confining pressure ratio is not much different, the plastic zone presents an elliptical distribution pattern. When the two-way confining pressure ratio is quite different, the plastic zone presents a butterfly distribution pattern. Rmax is the maximum distance from the center of the borehole to the boundary of the butterfly leaf, which is used in the manuscript to describe the maximum influence range of borehole gas extraction.
- The borehole numbers are too many in Figures 14 and 15, which conditions may apply such model?
The number of boreholes in Figure 14 and Figure 15 in the manuscript is mainly used to express the construction method of honeycomb gas flow network channel structure based on the distribution pattern of plastic zone of borehole surrounding rock, and the engineering application is universal. In practical engineering applications, it should also be combined with the thickness of the coal seam, the strength of the coal body and the size of the borehole aperture, but it must be based on the expansion of the plastic zone of the surrounding rock of the borehole, so as to promote the exchange of gas flow in the surrounding rock of each borehole.
- More details needed in the Engineering test part, include the field application process, the monitoring parameters, and the field test effect, etc.
According to the opinions of reviewers, We increased the test steps, gas concentration changes in the following figure.
1 ) Construction extraction drilling. Drilling extraction is carried out at the selected location, and different apertures and spacings are selected for construction.
2 ) Sealing and connecting pipe. The hole is sealed with a pre-prepared stopper or polyurethane, and the mixed liquid of cement mortar, expansion agent and accelerator is slowly injected into the hole with a grouting pump for sealing. After the construction of the extraction borehole is completed, the borehole is sealed in time and the connecting pipe is connected in time.
3 ) Observation data. The data of extraction parameters ( extraction negative pressure, extraction concentration, mixed flow, etc. ) were observed and recorded every day.
Author Response File: 
Author Response.docx
Reviewer 2 Report
1. The font size in Figure 5 varies, and the font style of the text in Figure 4 (c) is not uniform.
2. Some formulas in the article have inconsistent text sizes, such as formula (15).
3. The serial numbers (a) and (b) in Figure 2 are too close to the figure and should be separated.
4. The clarity of some images is too low, and the text descriptions in the images are unclear. Some text exceeds the boundary of the coordinate axis, as shown in Figure 3.
5. It is recommended to indicate the variables and units on the X and Y axes of all the figures in the article, as shown in Figures 3, 6, 7, etc.
6. The 'Fig.6 Distribution patterns of plastic zones in surrounding rock of boreholes under different coverage' in the text is redundant.
7. Suggest refining and simplifying the text in the article.
8. Some grammar suggestions for improvement in the article.
Author Response
REPLIES TO REVIEWERS’ COMMENTS
Dear Professor,
We thank you and the reviewers for considering our manuscript. Their comments have helped us revise and improve our manuscript. We have studied all comments and made the corresponding corrections. The language of the manuscript has also been improved. I hope it meets with your approval. All changes are indicated in red, and the response to each comment is provided below:
We thank you for the opportunity to resubmit our manuscript.
Sincerely yours,
Chao Yuan
Replies to Reviewer #2:
- The font size in Figure 5 varies, and the font style of the text in Figure 4 (c) is not uniform.
In view of the font size and format inconsistency in Figure 5 and Figure 4 ( c ), we have made serious modifications.
- Some formulas in the article have inconsistent text sizes, such as formula (15).
According to the opinions of reviewers, we have adjusted the formula text.
- The serial numbers (a) and (b) in Figure 2 are too close to the figure and should be separated.
We have adjusted the content of Figure 2.
- The clarity of some images is too low, and the text descriptions in the images are unclear. Some text exceeds the boundary of the coordinate axis, as shown in Figure 3.
According to the opinions of reviewers, we have re-adjusted all the picture content of the manuscript.
- It is recommended to indicate the variables and units on the X and Y axes of all the figures in the article, as shown in Figures 3, 6, 7, etc.
We have adjusted the contents of Figure 3,6,7 in the manuscript, adding units on the X and Y axes.
- The Fig.6 Distribution patterns of plastic zones in surrounding rock of boreholes under different coverage' in the text is redundant.
The distribution pattern and range of plastic zone in borehole surrounding rock are directly related to the strength of coal body. As the main parameters to characterize its strength, cohesion and internal friction angle of coal body must become the key factors affecting the permeability-increasing circle radius of surrounding rock. In order to ensure the integrity of the manuscript, please allow to retain Figure 6.
- Suggest refining and simplifying the text in the article
We have further improved and simplified the abstract and conclusion parts of the manuscript, focusing on the innovation and main research results of the manuscript.
- Some grammar suggestions for improvement in the article.
According to the opinions of reviewers, we also modified the English expression of the manuscript.
Author Response File: Author Response.docx
Reviewer 3 Report
In the paper entitled " Construction method of honeycomb gas flow network channel structure based and engineering response on plastic zone distribution form " , the manuscript demonstrates gas pressure parameters. Based on the modified Terzaghi effective stress principle and Mohr-Coulomb strength criterion, the implicit equation of the plastic zone boundary of the borehole surrounding rock is derived. The influence of the influence ratio of the two-way confining pressure, the strength of the coal body, the gas pressure and the pore size on the distribution of the plastic zone and the anti-reflection ring of the surrounding rock is analyzed. The honeycomb airflow network channel structure based on the distribution of the plastic zone is constructed, which realizes the connection and enrichment area of the coalbed methane flow and the anti-reflection ring, and improves the gas extraction rate.
I believe that before the manuscript is published, the following modifications or explanations are needed.
1. The simplified hypothesis part of the mechanical model of gas surrounding rock drilling is ideal, which is far from reality and may not achieve the simulation effect. Please make appropriate corrections or provide assumptions.
2. Based on the influence of the theory of coal drilling around rock permeability circle, it is hoped that the author can provide a way to obtain pictures to enhance its supporting effect.
3. In the construction method of honeycomb gas flow network channel structure, most of them are the introduction of the role of this method. The specific method is too vague. Please specify.
4. The second evidence in the conclusion is not sufficient, and I hope it can be supplemented.
5. Part of the picture in the article is too small, the overall view is not conducive to the display. Please adjust appropriately.
6. The abstract part is too simple, may not interest the reader, and can be appropriately expanded.
7. Some language content authors have native language expressions and can be revised.
Author Response
REPLIES TO REVIEWERS’ COMMENTS
Dear Professor,
We thank you and the reviewers for considering our manuscript. Their comments have helped us revise and improve our manuscript. We have studied all comments and made the corresponding corrections. The language of the manuscript has also been improved. I hope it meets with your approval. All changes are indicated in red, and the response to each comment is provided below:
We thank you for the opportunity to resubmit our manuscript.
Sincerely yours,
Chao Yuan
Replies to Reviewer #3:
- The simplified hypothesis part of the mechanical model of gas surrounding rock drilling is ideal, which is far from reality and may not achieve the simulation effect. Please make appropriate corrections or provide assumptions.
According to the opinions of reviewers, we added the following assumptions in the manuscript:
The surrounding rock mass is isotropic medium, ideal elastic-plastic body, and the coal body with good integrity can be regarded as isotropic continuous medium. Ignoring the mutual transformation between free gas and adsorbed gas in coal. The adsorption equilibrium of coal is destroyed after pressure relief, so that the adsorbed gas becomes free gas. In practice, it must be converted under special circumstances, so it can be ignored.
- Based on the influence of the theory of coal drilling around rock permeability circle, it is hoped that the author can provide a way to obtain pictures to enhance its supporting effect.
The pictures of the theoretical part of the seepage zone of the surrounding rock of the coal seam are based on the expression (15), and the visualization of the seepage zone of the surrounding rock of the borehole is realized by means of Matlab calculation software programming. The distribution of the plastic zone of the borehole and the influence of confining pressure ratio, coal strength, gas pressure and aperture on the plastic zone are presented.
- In the construction method of honeycomb gas flow network channel structure, most of them are the introduction of the role of this method. The specific method is too vague. Please specify.
The general idea of Structure of Honeycomb Gas Flow Network Channel ( SHGFNC ) is based on the distribution of plastic zone in borehole surrounding rock, and the key to form this structure is to determine the scientific and reasonable hole spacing. When the plastic zone of surrounding rock of each borehole can expand and form a honeycomb gas flow network channel structure, it is a scientific and reasonable gas drainage hole spacing. In the engineering test, when the borehole spacing is 5 m, the expansion of the plastic zone of the surrounding rock can be effectively realized.
- The second evidence in the conclusion is not sufficient, and I hope it can be supplemented.
In the manuscript, we have carefully revised the second problem of insufficient evidence in the conclusion and marked it in red font.
- Part of the picture in the article is too small, the overall view is not conducive to the display. Please adjust appropriately.
The image size has been adjusted.
- The abstract part is too simple, may not interest the reader, and can be appropriately expanded.
According to the opinions of the reviewers, we have adjusted all the pictures of the manuscript in order to achieve the best visual effect.
- Some language content authors have native language expressions and can be revised.
According to the opinions of reviewers, we also modified the English expression of the manuscript.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The current version can be accepted.
