Influence of Drilling Along Pilot Holes on Drilling Performance and Effective Rock Strength^†

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study focuses on optimizing drilling operations in complex geological formations, specifically using a Large-scale Drilling Simulator (LDS) to conduct experiments with gabbro samples. The LDS setup is described on Page 6, where it states, "The lab Large-scale Drilling Simulator (LDS) was used for all pre-cored holes and drilling experiments" . This simulator allowed for methodical testing of various drilling parameters, providing insights into the Rate of Penetration (ROP) and other performance metrics.

On page 4, the authors emphasize the importance of the data collected, noting that "the data collected from these experiments provided valuable insights into optimizing drilling operations in complex geological formations". This highlights the study's aim to enhance drilling efficiency through careful regulation of drilling conditions and the use of specialized tools.

The experiments involved a series of methodical stages to prepare the gabbro samples for drilling tests, as mentioned on Page 6: "This process involved a number of methodical stages to get the gabbro sample ready for drilling tests with different hole configurations" . The findings from these experiments are expected to contribute significantly to the understanding of drilling performance under varying geological conditions.

Overall, the document presents a comprehensive analysis of drilling performance, with a focus on the interplay between drilling parameters and geological formations. The insights gained from this research are crucial for improving drilling strategies and operational efficiency in the field.

Author Response

For the research article Influence of drilling along pilot holes on drilling performance and effective rock Strength

Response to Reviewer

1. Summary
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the revisions/corrections highlighted/in track changes in the re-submitted files.   Comments 1

The study focuses on optimizing drilling operations in complex geological formations, specifically using a Large-scale Drilling Simulator (LDS) to conduct experiments with gabbro samples. The LDS setup is described on Page 6, stating, "The lab Large-scale Drilling Simulator (LDS) was used for all pre-cored holes and drilling experiments" . This simulator allowed for methodical testing of various drilling parameters, providing insights into the Rate of Penetration (ROP) and other performance metrics.

Response 1:

I have modified and added it

Comments 2

On page 4, the authors emphasize the importance of the data collected, noting that "the data collected from these experiments provided valuable insights into optimizing drilling operations in complex geological formations". This highlights the study's aim to enhance drilling efficiency through careful regulation of drilling conditions and the use of specialized tools.

I reconsider and change.

The experiments involved a series of methodical stages to prepare the gabbro samples for drilling tests, as mentioned on Page 6: "This process involved a number of methodical stages to get the gabbro sample ready for drilling tests with different hole configurations" . The findings from these experiments are expected to contribute significantly to the understanding of drilling performance under varying geological conditions.

Response 3:

I reconsider and change.

Comments3

Overall, the document presents a comprehensive analysis of drilling performance, focusing on the interplay between drilling parameters and geological formations. The insights gained from this research are crucial for improving drilling strategies and operational efficiency in the field.

Response 4:

I have edited the manuscript again for grammar and stylistic mistakes.

I have reduced the number of self-citation references as indicated.

.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript's authors titled “Investigation of drilling along pilot holes on drilling performance and effective rock strength”. Current research presented the experimental results of the investigation of pilot hole drilling technique on the drilling performance of rock. The authors made a detailed analysis of the state of the art in the field. They presented a description of the experimental set-up and experimental procedure, as well as a description of the drill bit. The manuscript topic is relevant to research and engineering communities in the field. The structure of the manuscript and results presentation is hard to understand. Feature recommendations are aimed at improving the manuscript structure and results presentation.

 

1.       Please reconsider the text in Chapter 2. The confusing aspect is that the authors combined the description of the experimental procedure with the description of the results. Namely, sentences Line (88-91) and Line (97-102) are not logical to appear in this part of the manuscript. It is recommended that these sentences be deleted or transferred to the results and discussion section.

2.       It is clear from the manuscript what was the exact number of experimental runs and what the conditions of these runs were. It is recommended to add the table of the design of the experiment in Chapter 2 to clarify the conditions and factors considered in the experiment set up.

3.       Also, it is recommended to present the experimental procedure as a structural scheme instead of a wordy explanation (Subchapters 2.1, 2.2), which confuses the reader instead of clarifying the procedure.

4.       Please add the table with specifications of mechanical, physical or other parameters of sample material.

5.        It is recommended to add drawings of cutters with the combination of cutters photos on figure 1 for each cutter type used in the experiment.

6.        The description of the experimental setup should be reconsidered. The current description does not give a sufficient understanding of the technical characteristics of the Large drilling simulation machine and measuring equipment and its technical characteristics. Please correct this.

7.       How data at Figure 7 was measured. The description of figures 7 and 8 does not add any understanding of the presented data; so far, it describes the obvious graphical aspects but does not explain the phenomena this data represents. Please reconsider the analysis of results for figures 7 and 8. Moreover, what is the purpose of Figure 8? It shows the linear relationship between time and cutter position, however it is obvious if the rotation and feed of the cutter is constant during drilling process. Please give more sufficient explanations of the necessity of the Figure 8

8.       How torques in Figure 9 were measured? Please and the description measuring devices and measuring technique in Chapter 2 (Experimental procedure)

9.       Why did Y-axe at Figure 5 start from 10.5 cm? And ones again this figure should be moved to the results section.

10.   Citation  “Overall, this process involved a number of methodical stages to get the gabbro sample ready for drilling tests with different hole configurations” (Line 211-212). The description of this stage is wordy and complicated. It is recommended to present these methodological stages in the form of structural and logic scheme.

11.   So far, they are no design of the experiment. It is hard to understand what information is presented in Figures 9, 10, 11, and 12. Is this result of one single experimental run with three repetitions, or are there three different experimental runs?

12.   Citation “….Figure 10 of the torque and 275 ROP detect the correlation between them” (Line 275-276). How did the authors come to this statement? Did the authors make a correlation analysis of this relationship? If “yes”, please add the results of correlation analysis calculations.

13.   Please reconsider the conclusion section. The main disadvantage of the conclusion section is that it is written in general form and does not support the reader with specific experimental research outcomes. Focusing on the main results is recommended instead of describing non-essential aspects. In conclusion, it would be better if the author emphasised quantity measures of gained results in absolute or relative values.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The manuscript has many gramatical and stylistic mistakes. 

Author Response

For the research article Influence of Drilling Along Pilot Holes on Drilling Performance and Effective Rock Strength

 

1. Summary
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

 

Comment 1

• Please reconsider the text in Chapter 2. The confusing aspect is that the authors combined the description of the experimental procedure with the description of the results. Namely, sentences Line (88-91) and Line (97-102) are not logical to appear in this part of the manuscript. It is recommended that these sentences be deleted or transferred to the results and discussion section.

Response 1:   As you recommended, the sentences Line (88-91) and Line (97-102) deleted

Comment 2. It is clear from the manuscript what the exact number of experimental runs and what the conditions of these runs were. It is recommended that the table of the experiment design be added in Chapter 2 to clarify the conditions and factors considered in the experiment setup.

Response 2 : I add the table of the design of the experiment in Chapter 2

Comment 3. Also, it is recommended that the experimental procedure be presented as a structural scheme instead of a wordy explanation (Subchapters 2.1, 2.2), which confuses the reader and does not clarify the procedure.

Response 3: As you recommended, I created the experimental procedure as a structural scheme instead and kept explaining the experimental procedure for more clarification. As you can see on pages 5,6

Comment 4. Please add the table with specifications of mechanical, physical or other parameters of sample material.

Response 4: I have added the table on page 3, line 107

Comment 5. It is recommended to add drawings of cutters with the combination of cutters photos in Figure 1 for the cutter type used in the experiment.

Response 5: I removed the combined PDC bit because it is not used in the experiment, as you can see in Figure 1, page 4

Comment 6. The description of the experimental setup should be reconsidered. The current description does not give a sufficient understanding of the technical characteristics of the large drilling simulation machine and measuring equipment and its technical characteristics. Please correct this.

Response 6: I have added the specifications on page 7, lines 187 to 203, for the large drilling simulation machine, measuring equipment, and technical characteristics.

Comment 7. How data in Figure 7 was measured. The description of Figures 7 and 8 does not add any understanding of the presented data; so far, it describes the obvious graphical aspects but does not explain the phenomena this data represents. Please reconsider the analysis of results for Figures 7 and 8. Moreover, what is the purpose of Figure 8? It shows the linear relationship between time and cutter position. However, it is obvious if the rotation and feed of the cutter are constant during the drilling process. Please give more sufficient explanations of the necessity of Figure 8

Response 7: I reconsider the present analysis of the results, which show how they were measured and the purpose of Figure 8 on page 8, lines 225 to 239.

Comment 8. How were torques in Figure 9 measured? Please provide the description of measuring devices and measuring technique in Chapter 2 (Experimental procedure)

Response 8: Torque is mastered by a large drilling simulation machine, which comes from an Electric Motor Torque Formula controlled by LabVIEW, so I added the formula on page 7, line 198

Comment 9. Why did Y-axe at Figure 5 start from 10.5 cm? Once again, this figure should be moved to the

results section.

Response 9: I have modified the figure to start with 0 and also removed the result section on page 13  

Comment 10. Citation: “Overall, this process involved a number of methodical stages to get the gabbro sample ready for drilling tests with different hole configurations” (Line 211-212). The description of this stage is wordy and complicated. It is recommended to present these methodological stages in the form of structural and logic schemes

Response 10:  I add the structural scheme for both experiment 

Comment 11. So far, there are no designs for the experiment. It is hard to understand what information is presented in Figures 9, 10, 11, and 12. Is this result of one single experimental run with three repetitions, or are there three different experimental runs?

Response 11: It is the result of one single experimental run with three repetitions on page 8, line 227

Comment 12. Citation “.... Figure 10 of the torque and 275 ROP detect the correlation between them” (Line 275-276). How did the authors come to this statement? Did the authors make a correlation analysis of this relationship? If “yes”, please add the results of correlation analysis calculations.

Response 12: No, I did not do a correlation, so I have modified this citation for more clarification on page 9, line 274

Comment 13. Please reconsider the conclusion section. The main disadvantage of the conclusion section is that it is written in general form and does not support the reader with specific experimental research outcomes. Focusing on the main results is recommended instead of describing non-essential aspects. In conclusion, it would be better if the author emphasized quantity measures of gained results in absolute or relative values.

Response 13 As you recommended, I reconsider the conclusion as emphasized quantity measures of gained results in absolute or relative values on page 20

Comment 14: The manuscript has many grammar and stylistic mistakes.

Response 14: I have Editor the manuscript again

Response15: I have reduced the number of self-citation references as indicated.

Reviewer 3 Report

Comments and Suggestions for Authors

The paper is on study of drilling along pilot holes on drilling performance and effective rock strength. It seems like comprehensive laboratory report providing a lot of information and missing the explanation of the relationship between the variables and the measured properties. Also,  the paper is too long. Several figures should be removed as they do not provide any important information. There are too many variables making it difficult for reading. The comments and suggestions are listed below. In general, it would be essential to shorten paper and include missing discussion.

a)     The abstract is too long and unreadable. Authors should shorten the abstract.

b)     Line 287: please explain WHY the structural properties of the drilled formation have a major impact on drilling success?

c)     Line 340: Please put adequate reference.

d)     Line 568: “Using the Modified Maurer model to analyze the impact of pilot hole diameter on  effective rock strength, Especially at higher WOB values.”-this part is unclear.

e)     Author should write conclusion after discussion. Line 571-585: this should stand in discussion part.

f)      Authors should provide micrographs to improve manuscript.

 

 

Author Response

For the research article Influence of Drilling Along Pilot Holes on Drilling Performance and Effective Rock Strength

Response to Reviewer

1. Summary

Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the revisions/corrections highlighted/in track changes in the re-submitted files.

Response: I have edited the manuscript again for grammar and stylistic mistakes.

Response: reduce the number of self-citations as indicated

Comments 1)     The abstract is too long and unreadable. Authors should shorten the abstract.

Response 1: I modified. The abstract was condensed for clarity.

Comments 2)    Line 287: please explain WHY the structural properties of the drilled formation have a major impact on drilling success.

Response 2I explain in line.

The structural properties of the drilled formation, such as rock strength, fracture density, and mineral composition, significantly impact drilling success due to their influence on bit-rock interactions. High-strength formations require greater energy for penetration, which can lead to increased torque and slower ROP. Conversely, pre-existing fractures or weaker material integrity in pre-cored formations reduce resistance, enhancing ROP while introducing complexities in torque response. These structural differences dictate the mechanical energy (MSE) required for drilling, affecting efficiency and tool wear. Understanding these properties is crucial for improving drilling strategies, as they determine how effectively the drill bit interacts with the rock.

Comments 3)     Line 340: Please put adequate references.

Response 3: Improved references

Comments 4)     Line 568: “Using the Modified Maurer model to analyze the impact of pilot hole diameter on effective rock strength, especially at higher WOB values.”-this part is unclear.

Response 4: I have modified line 589

Comments 5) The author should write the conclusion after the discussion. Line 571-585: this should stand in the discussion part.

Response 5: I reconsider the conclusion again and add a discussion.

Comments 6)      Authors should provide micrographs to improve the manuscript.

Response 6: Micrographs need a lot of time to process, and the device needs to be installed on our label.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

the authors made sufficient corrections and consider all reviwers comments

Author Response

For the research article Influence of Drilling Along Pilot Holes on Drilling Performance and Effective Rock Strength

 

1. Summary
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

Reviewer 3 Report

Comments and Suggestions for Authors

 

The manuscript has NOT 
sufficiently improved to warrant publication in Applied Sciences. 

It seems like comprehensive laboratory report providing a lot of information and missing the explanation of the relationship between the variables and the measured properties. Also,  the paper is too long. Several figures should be removed as they do not provide any important information. There are too many variables making it difficult for reading. In general, it would be essential to shorten paper and write as scientific one !

Author Response

For the research article Influence of Drilling Along Pilot Holes on Drilling Performance and Effective Rock Strength

 

1. Summary
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.

Comment 1

It seems like a comprehensive laboratory report provides a lot of information and is missing an explanation of the relationship between the variables and the measured properties.

Response 1:  

I have revised and clarified the abstract, research methodology, and experimental procedure sections to better articulate these connections and provide a more cohesive understanding of the study

Comment 2

 Also, the paper is too long. Several figures should be removed as they do not provide any important information.

Response 2:  

I have modified the document by removing figures 6 to 12 and replacing them with tables 4 and 5. This change ensures clarity and relevance while aligning with the overall objectives of our work. It is essential to preserve the key contributions and insights of the study.  Any figures can be explained and modified if they do not provide any important information.

Comment 3

There are too many variables, making it difficult to read. In general, it would be essential to shorten the paper and write it as a scientific one!

Response 3:  

I have modified and added descriptions of these variables, making it an essay to read.