Modeling of Swab and Surge Pressures: A Survey

Round 1

Reviewer 1 Report

This paper offers a survey of the available methods to estimate the surge and swab pressures which take place when the drill string during a trip in/out procedure. This issue is well known to the drilling engineering community and has led to significant problems in many drilling operations which may lead to the collapse and abandonment of the hole. Clearly, any method to estimate them would be warmly welcome by the industry as it would provide guidelines to the drillers so as to minimize or even wipe out such issues.

The paper is well written and the description of the existing rigorous, physics driven methodologies is clear and extended as far as both the mathematical and the physical background is concerned. I fail to see how the last section (Proposal for a new research) is related to the previous sections in a "Survey context". That content is quite trivial and only discusses about some very basic ideas/guidelines on how a data-driven approach could be developed once data becomes available. Section 3.1 simply describes current technology in MWD whereas section 3.2 descrobes the basic steps to develop a typical machine learning based system.

I regret to say that this work should not be published as, firstly, its topic is too specialized for the Journal that it has been submitted to and, secondly, because it provides nothing new other than a detailed review of a bunch of estimation methods which, in my modest opinion, are not of interest to the readers of this Journal.

Author Response

Please see the attached PDF file.

Author Response File: Author Response.pdf

Reviewer 2 Report

I would like to thank the authors for this study, The new version  of this paper is way better compared to the original version. Just table number 5 need some justification.  

Author Response

Please see the attached PDF file.

Author Response File: Author Response.pdf

Reviewer 3 Report

 A comprehensive review of surge and swab pressure models was provided in this study, and key strengths and weakness were explored. Overall, this a very relevant topic with great significance for drilling engineering. However, surge/swab pressure has been extensively studied as this problem has been known for decades. Thus, this reviewer believes this paper is incomplete and must be completely reworked to be published for the following reasons:

 

1. The literature review only describes five models. A significant number of relevant works is missing (e.g. Lubinski et al. (1977) and mention to the pioneer works by Cannon (1934) and Goins et al (1955) should also be added, as well as more recent works.

 

2. The authors enter in too many details about each model including listing all equations and variables, when simply presenting the main idea, the outcomes and limitations would suffice.

 

3. No comparison between the models’ predictions was presented. This reviewer recommends running a few examples and comparing the deviation in the final result either as a plot or table to assist the readers.

 

4. In section 3, the authors suggest that new research should focus on a data-driven approach to calculate surge and swab pressures. However, many works using data analytics have already been published, including real time predictions. The authors should consider reviewing some of these works in the paper and then discussing their benefits and what could be improved.

 

5. The authors draw conclusions that are not supported on the text since no examples of surge/swab data-driven models were presented.

 

 

Additional comments.

1. This reviewer recommend including the name of the authors when citing a model (e.g. Mitchell [3])

 

2. Please display the tables’ caption above the table.

 

3. Please avoid using citations in the Conclusion section

Author Response

Please see the attached PDF file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

No comments to the authors

Author Response

Review-round III: Point-to-point response to the reviewers’ comments:

--------  REVIEWER-1: ------------

Reviewer-1 Comment-1:

This reviewer greatly appreciates the authors' work in the manuscript to address many of the technical shortcomings identified in the earlier draft. However, as noted previously, this reviewer still finds the paper incomplete as the main concerns remain. As it is, the paper makes no contribution to existing material in the research area. The authors argue that a more complete literature review would make the paper very long, but review papers can easily surpass a hundred citations; it just needs to be better structured. The discussion section remains very vague, and no evidence of the benefits of a data-driven model for this case is presented. This reviewer would suggest the authors present the current state of knowledge of data-driven models for surge/swab before claiming the proposed approach is more advanced.

 

Authors’ response:

Dear Sir or Madam,

Thank you very much for suggesting improvements for our paper. Your pursuit for perfection helps us improve our paper dramatically. Thank you very much!

 

We have added a completely new section (section-3) on "Data-Driven Modelling in Drilling in Well Operations." This section is right after the summary of the models. This new section is succeeded by our own proposal for new research on swab & surge (section-4  "Proposal for New Research on Surge & Swab Pressure Modeling"). 

Please see the revised paper for the new section-3.     

Author Response File: Author Response.pdf

Reviewer 3 Report

This reviewer greatly appreciates the authors' work in the manuscript to address many of the technical shortcomings identified in the earlier draft. However, as noted previously, this reviewer still finds the paper incomplete as the main concerns remain. As it is, the paper makes no contribution to existing material in the research area. The authors argue that a more complete literature review would make the paper very long, but review papers can easily surpass a hundred citations; it just needs to be better structured. The discussion section remains very vague, and no evidence of the benefits of a data-driven model for this case is presented. This reviewer would suggest the authors present the current state of knowledge of data-driven models for surge/swab before claiming the proposed approach is more advanced.

Author Response

Review-round III: Point-to-point response to the reviewers’ comments:

--------  REVIEWER-2: ------------

 

Reviewer-1 Comment-1:

This reviewer greatly appreciates the authors' work in the manuscript to address many of the technical shortcomings identified in the earlier draft. However, as noted previously, this reviewer still finds the paper incomplete as the main concerns remain. As it is, the paper makes no contribution to existing material in the research area. The authors argue that a more complete literature review would make the paper very long, but review papers can easily surpass a hundred citations; it just needs to be better structured. The discussion section remains very vague, and no evidence of the benefits of a data-driven model for this case is presented. This reviewer would suggest the authors present the current state of knowledge of data-driven models for surge/swab before claiming the proposed approach is more advanced.

 

Authors’ response:

Dear Sir or Madam,

Thank you very much for suggesting improvements for our paper. Your pursuit for perfection helps us improve our paper dramatically. Thank you very much!

 

We have added a completely new section (section-3) on "Data-Driven Modelling in Drilling in Well Operations." This section is right after the summary of the models. This new section is succeeded by our own proposal for new research on swab & surge (section-4  "Proposal for New Research on Surge & Swab Pressure Modeling"). 

Please see the revised paper for the new section-3.     

 

Author Response File: Author Response.pdf

Round 3

Reviewer 3 Report

Authors address my comments successfully. Thus, I recommend the manuscript  for publication 

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Dear authors,

The paper is easy to read and the topic is interesting. However, the content and structure of the paper needs significant revisions to effectively communicate your hard work and achieve publication quality. Following is my specific feedback: 

1. There is no negative absolute pressure. So instead of saying “Pressure is positive when lowering and negative when withdrawing” (abstract line 2) describe swab/surge in terms of relative pressure difference and direction of flow between bottom hole and reservoir.
2. It would be easier for readers to follow if you mention authors’ names while discussing a model. For example, “[2] developed a model” can be rephrased as “Schuh et al [2] developed a model..”. Similarly title of section 2.1 can be rephrased as “Lal’s model for dynamic …”
3. Reference for Figure 1?
4. No limitations of the model in section 2.1?
5. Fix table 5 and 6 formatting. Are they mistakenly separated? Why two separate tables to summarize the models?
6. For a thorough analysis of models, did you consider using an example dataset, run it through these models, and see how different are their predictions? 
7. I think some of the discussions in the paper are too detailed or unnecessary considering the scope of the paper. For example, MWD and LWD descriptions on page 22 must be brief. Some of the model discussion are also too detailed. Readers can always refer to the original papers for specific details. The purpose of your analysis and review should be to emphasize benefits, limitations, approach of the model. Your model summary tables are good but could be improved.
8. Considering the nature of work presented in the paper, it is imperative that exhaustive literature review of swab and surge modelling and other relevant studies is presented. The literature review must be expanded. A simple search reveals several publications on this topic from authors such as Bjorkevoll, Tikhonov, Chandrasekhar, Erge, Samuel, Zhao, Chin, etc. The models discussed in the paper (except Gjerstad and Srivastava), are more than 30 years old. Please add more literature review and expand discussion on recent works.
9. Conclusions section must be revised. It is also important to differentiate summary from conclusions. Summary should simply provide overview of your work and what has been presented in the paper, particularly a quick summary of various types of models. The conclusions section should highlight practical and bigger picture aspects or the learnings from the presented work such as key takeaways, implications, limitations, research gaps, etc.
10. There are several grammatical/semantics errors throughout the paper. Please check the whole paper carefully. Following are some of the issues I noticed through a quick review but there could be more issues. Kindly check.
    • Line 52 – Do you mean ‘six’ prominent works?
    • Line 80 - No space in between number and unit
    • Line 62 – ‘Diamond drill bits’
    • Line 258 – ‘Outer diameter / surface..’
    • Line 263 – ‘The precise.’
    • Table 5 caption missing

Reviewer 2 Report

This paper deals with the estimation of the surge and swab pressures which take place when the drill string is in a trip in or out procedure. This issue is well known in the drilling engineering community and has led to significant problems in many drilling operations which may lead to the collapse and abandonment of the hole. Clearly, any method to estimate them would be warmly welcome by the industry as it would provide guidelines to the drillers so as to minimize or even wipe out such issues.

The paper is well written and the description of the existing rigorous, physics driven methodologies is clear and extended as far as both the mathematical and the physical background is concerned. It also gives some very generic and rather vague guidelines on how a data-driven approach could be developed once data becomes available.

Nevertheless, I regret to say that it should not be published as, firstly, its topic is too specialized for the Journal that it has been submitted to and, secondly, because it provides nothing new other than a detailed review of a bunch of estimation methods which, in my modest opinion, are not of interest to the Journal readers.

Reviewer 3 Report

I would like to thank the authors for this study, which targeting an interesting industrial title “Modeling of Swab and Surge Pressures”.

The following points must be covered:

• The paper presented a review for the previous work without any new information.
• All presented equations must be presented in equation form not as a figure caption.
• The introduction is too long and presented in poor scientific way.
• Each previous model must be presented in a strong/week points, and showing how the next work tried to cover this issue.
• By the end of introduction, the author must present the gab to be covered in the presented paper.
• The author should provide a new model to cover a previous issue, or change the paper title to be a review paper and rewrite it in a new form.

 

 

Comments for author File: Comments.pdf