Distribution Characteristics and Cause Analysis of Casing Deformation during Hydraulic Fracturing of Shale Gas Wells
Round 1
Reviewer 1 Report
The article is hard to understand because of the language and not sufficient explanations of the research performed. The last paragraph of the introduction contain an information “the following is the research methodology”, but there is really no information about the methodology. What kind of measurements were used to the numerical modelling? What devices were collecting the parameters? These are just some of the questions that arise after reading the article.
What is missing is also an attempt to generalize the results, compare them with other studies and a discussion, which was observed during the analyses. Meanwhile, the authors focus mainly on describing the methods of modelling, without showing the importance of their research for science or technology.
The analysis under figure 2 contains only the readings of the results shown in the figure. However, there is no explanation of what the strange abbreviations under individual bars mean, or what results from the comparison.
Many figures and tables shown distribution features of the casing deformation points, but there is no information about the goal of those analyses.
Also the sensitivity analysis shows results that are difficult to interpret. The authors did not provide the sensitivity analysis methodology (or at least the formula for its calculation) and did not provide which of the independent variables would have the greatest impact on the result.
The language of work also needs to be significantly improved. The following sentences have the same structure and the whole paper is difficult to understand.
The conclusions have no scientific statements and are only 3 sentences long, which cannot be accepted.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
First of all, instead of the mdpi Journal "Processes" I would rather recommend another mdpi Journal such as "Applied Sciences".
The paper has high practical interest in engineering and could deserve publication in the adequate journal. However, from the purely scientific point of view, it contains serious flaws and lacks of rigour, mainly, there is no proper definition of a fundamental fracture/failure criterion. It seems to be based on deformation/strain (or, roughly speaking, engineering displacement), but this important issue must be properly clarified before the paper being accepted for publication.
The aforesaid lack of scientific rigour also appears in a common confusion between strain/deformation (dimensionless variable) and displacement (with units of length), with the tremendous mistake of expressing a deformation in units of length (e.g., see milimiters in Figure 16). It the authors by deformation try to indicate not strain (as commonly understood in continuum mechanics text books) but displament, they must properly indicate so with an adequate definition.
In addition to the aforesaid fundamental problemms of the paper, the authors must clarify the real engineering proble (e.g., Figure 5) to let the readers understand the paper.
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
All suggestions were implemented. Especially conclussions and results explanations were corrected. Also the language is proper at the last version of the manuscript. I have no other objections.
Reviewer 2 Report
The authors have correctly addressed the suggestions.
The paper can be published now.
