A Novel Prediction Model for Steam Temperature Field of Downhole Multi-Thermal Fluid Generator
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors,
see the attached file
Comments for author File: 
Comments.pdf
Minor editing required
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsIt appears that the paper submitted is for a special issue entitled: "Artificial Intelligence Techniques in the Optimal Operation of Oil and Gas Production Systems". However, I have read the paper thoroughly and I did not spot any AI techniques used for the solution of the heat equations. In fact, I searched the whole paper with the keywords "articificial" and "intelligence" and I got no results, not even in the introduction section. Therefore, I have to reject the submitted manuscript for this special issue.
Therefore, I have to reject the paper for publication in this special issue.
Comments on the Quality of English LanguageEnglish must be improved.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe work presents a theoretical and numerical analysis of steam temperature field of a down-hole multi-thermal fluid generator. Predictions with a simplified theoretical model and a CFD model are presented. The work is of potential interest to the journal, but revision of some aspects is necessary. The authors must address the following points:
• The theoretical and numerical predictions must be validated with experimental data.
• A grid refinement study of the CFD model must be included.
• The effect of local temperature on thermal and fluid properties must be discussed.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors,
in my opinion now the paper can be published.
Comments on the Quality of English LanguageMinor editing required
Author Response
Thank you very much for your advice. We have polished our manuscript carefully and corrected the grammatical, styling, and typos found in our manuscript.
Reviewer 2 Report
Comments and Suggestions for Authors1. Since this is a special issue on "Artificial Intelligence Techniques....." the authors must add a separate paragraph somewhere in the text and make comments on how their present study is, or can be, connected to the AI concept. The authors in their reply have sent me a bunch of references on AI techniques. Why don't they actually use these references in their manuscript and provide appropriate text around them, in conjuction to their study? This is absolutely necessary not only in the main text but the abstract as well.
2. Figure 1 is not acceptable. It is very difficult to discern each region. I believe it is the mechanical drawing with the real dimensions but it needs to be replaced with a schematic representation where each region is clear.
3. There is a typo in line 117 and line 262 (Table 350?). I have also seen other typos in the manuscript (like, author missing in ref. 29), so a thorough check must be carried out.
4. Searching in several databases and through the internet, I did not find reference 45, from which the authors used Eq. (9). Empirical correlations like Eq. (9) for forced convection heat transfer coefficients (Nusselt number) for inflows and outflows are available in several heat transfer textbooks. It is puzzling to me why the authors do not make reference to any standard heat transfer textbooks. Eq. (9) must be written in the form of Nusselt number (Nu number definition must be also given) and its use must be fully justified for the problem the authors study and provide the text-book from where it was taken.
5. Moreover, in line 169 the authors claim that Cφ is the "angular modification factor". What does it represent, physical meaning? Does it have any units? What is the value the authors use? A detailed explanation must be given on what this factor is, what value the authors used and why did they choose this value.
6. In table 6 dimensions and properties are given. The authors must provide references for the values of the properties they used.
7. It is difficult to understand mesh quality in Figure 6. This figure must be either removed or provide magnified views of the mesh regions where the highest temperature gradients are expected. Also, the text from line 254 to line 259 does not make sense (English check). A detailed explanation on the numerical technique used must be provided (e.g. structured or unstructred mesh, discretization scheme etc). Also, the heat equation ANSYS solves must be reported.
8. Technically, the word "simulation", especially in heat transfer analysis, means numerical simulation. The title of section 4.1.1. must be "Experimental measurements". Now, this section is poorly described. First of all, a picture of the device must provided and all of its parts must be identified. The model of the temperature probes used must be also provided and if and how the probes were calibrated. Also, the measuring error of the probes must be included. How was oil, water, air and high-temperature steam injected? There are no explanations on the devices used i.e. pumps, tubes, tube material etc. These must be provided. Furthermore, the credibility of the measured results in Fig. 5 are questionable. Is the annulus temperature for each well depth, an average value or just a single experiment? At least three experiments must be carried out to verify that their measuring device produces repetitive and consistent results. A table must be included showing the results of at least three experiments, and the averaged values.
If all the above are fully met, then the paper can be published.
Comments on the Quality of English LanguageNeeds to be further checked thoroughly.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
