Study on Sealing Performance of Spring-Embedded Shoulder Protection Packer Rubber Cylinder
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe details of the mesh are missing. Authors can elaborate
Details of the boundary conditions are missing
Was any mesh sensitivity analysis performed?
Discussion should be more elaborate.
What does “Revised sentence: …” in page 4 indicate?
The manuscript needs a major revision to improve the quality
Comments on the Quality of English LanguageNeed proofreading
Author Response
Thank you for your comments and suggestions on the manuscript. They are of great importance for us to improve the written quality of the currently work and give guidance for the future work. Your queries are answered one by one as follows.
Point 1: The details of the mesh are missing. Authors can elaborate Details of the boundary conditions are missing
Response 1: In terms of mesh division, the mesh of the upper and lower rubber cylinders is divided by free division method, and the mesh type is triangle and the mesh size is 1.5; the metal mesh in the side rubber cylinder is divided by free division method, the mesh type is quadrilateral and the mesh size is 1; the middle rubber cylinder is divided by free division method, the mesh type is triangle and the mesh size is 1.5. The upper and lower spacer rings and pressure rings are divided by the method of free division. The mesh type is quadrilateral and the mesh size is 2. As for the setting of boundary conditions, the lower pressure ring is fixed in the XY direction and the upper and lower spacer ring in the X direction to prevent the spacer ring from moving left and right during the setting process. The reference point is set at the upper pressure ring and the load is applied in the Y direction of the reference point position.
Point 2: Was any mesh sensitivity analysis performed?
Response 2: We conducted grid independence verification, and verified mesh sizes of 1mm, 1.2mm, 1.5mm, 1.8mm, 2.0mm. According to the results of grid independence verification, the selected mesh size has little influence on the calculation results. According to the mesh independence literature research results and the past experience of finite element simulation, the mesh quality is better than other sizes when the mesh size is 1.5mm, so the mesh size is 1.5mm. Considering the overall layout of the paper, we did not include the result of grid division in the paper because the two-dimensional model grid division is relatively simple. The mesh division results of the rubber cylinder are shown in the figure below.
Point 3: Discussion should be more elaborate.
Response 3: Thank the reviewers for their comments. The percentage reduction of axial compression distance in Section 3.2.1 was supplemented, the percentage reduction of maximum Mises stress in section 3.2.2 was supplemented, and the percentage increase of sealing performance factor in section 3.2.4 was supplemented.
Point 4: What does “Revised sentence: …” in page 4 indicate?
Response 4: Thank the reviewers for their comments. “Revised sentence: …” is an error occurred during the revision of the article and has been deleted.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors- How was the finite element model validated? Were there any experimental results used for comparison?
- Why was the Mooney Rivlin model chosen over other rubber constitutive models? Can you provide more detail on the fitting process for the material parameters?
- Can you provide more insight into the implications of a 3% increase in compression distance for the spring-embedded design? How does this affect the overall performance and reliability in real-world applications?
- The contact stress distribution shows improvements in the spring-embedded design. How does the increased contact stress and length directly correlate to better sealing performance? Are there any potential drawbacks to this design in terms of wear and tear on the casing?
- - In order to increase the depth of your article on the sealing of polymeric parts and to provide readers with more useful information, please refer to these two articles in detail.
Characterization of polypropylene pulsating heat stripes: Effects of orientation, heat transfer fluid, and loop geometry
https://doi.org/10.1016/j.applthermaleng.2020.116304
Investigation on the sealing performance of polymers at ultra high pressures
https://doi.org/10.1515/ipp-2022-4226
- While the manuscript demonstrates improved performance under specific conditions, how broadly can this design be applied across different types of packers and operating environments? Are there any limitations or conditions where this design might not perform as well?
- What are the next steps in this research? Are there any planned experimental validations or further optimization studies for the design?
Author Response
Response to Reviewer 2 Comments
Thank you for your comments and suggestions on the manuscript. They are of great importance for us to improve the written quality of the currently work and give guidance for the future work. Your queries are answered one by one as follows.
Point 1: How was the finite element model validated? Were there any experimental results used for comparison?
Response 1:We did not test the finite element model. The rubber material parameters used in finite element simulation are obtained through uniaxial tensile test. In addition, we produced actual rubber cylinder products according to the model, and we verified the tightness of the rubber cylinder products, and the rubber cylinder products were applied in the high temperature underground.
Point 2: Why was the Mooney Rivlin model chosen over other rubber constitutive models? Can you provide more detail on the fitting process for the material parameters?
Response 2: The commonly used hyperelastic models are Neo-Hooken model, Mooney-Rivlin model and Yeoh model. The sample made of rubber material used in the rubber cylinder at 25℃ and 177℃ was selected for uniaxial tensile test, and the obtained data were fitted in the engineering data module of Ansys Workbench for curve fitting. The fitting results were shown in the figure below. According to the fitting curve, the fitting degree of the Mooney-Rivlin2 parameter is the best, so the Mooney-Rivlin2 parameter model is selected.
(a)Neo-Hooken (b) Mooney-Rivlin2 (c)Yeoh3
Point 3: Can you provide more insight into the implications of a 3% increase in compression distance for the spring-embedded design? How does this affect the overall performance and reliability in real-world applications?
Response 3: At 25℃, the axial compression distance between the spring-embedded shoulder protection packer rubber cylinder and the traditional packer casing is the same, and at 177℃, the axial compression distance between the spring shoulder packer casing and the traditional packer casing is reduced by 3%. The statement "under the same temperature and load, the axial compression distance is reduced by 3%" in the paper is inaccurate and it has been revised. In Figure 3 (d) of the paper, the cloud map of axial compression distance of the spring shoulder packer cylinder is wrong and has been modified. At 177℃, compared with the traditional packer casing, the axial compression distance of the spring-embedded shoulder protection packer rubber cylinder becomes smaller, and the internal contact with the casing becomes longer, which increases the contact line length between the casing and the casing, and improves the sealing performance and reliability of the casing.
Point 4: The contact stress distribution shows improvements in the spring-embedded design. How does the increased contact stress and length directly correlate to better sealing performance? Are there any potential drawbacks to this design in terms of wear and tear on the casing?
Response 4: According to the sealing mechanism, the longer the contact length between the rubber cylinder and the casing wall, the larger the contact area between the rubber cylinder and the casing, the better the sealing performance; The greater the contact stress between the cartridge and the casing wall, the better the sealing performance of the packer cartridge. The spring and the metal mesh are embedded in the inside of the rubber cylinder, in fact, there is no direct contact with the casing, and the two will not wear the casing. The contact stress between the cartridge and the casing of the Spring-embedded shoulder protection packer rubber cylinder is greater than that between the traditional cartridge and the casing, and the increased contact stress is far less than the stiffness of the casing, there is no wear problem.
Point 5: In order to increase the depth of your article on the sealing of polymeric parts and to provide readers with more useful information, please refer to these two articles in detail.
Characterization of polypropylene pulsating heat stripes: Effects of orientation, heat transfer fluid, and loop geometry
https://doi.org/10.1016/j.applthermaleng.2020.116304
Investigation on the sealing performance of polymers at ultra high pressures
https://doi.org/10.1515/ipp-2022-4226
Response 5 Thanks to the literature recommendation of the reviewers, we have added these two literatures into the citation numbers 21 and 22.
Point 6: While the manuscript demonstrates improved performance under specific conditions, how broadly can this design be applied across different types of packers and operating environments? Are there any limitations or conditions where this design might not perform as well?
Response 6: Spring-embedded shoulder protection packer rubber cylinder can be used on compression packers. When the ambient temperature is above 150℃, the rubber material will flow phenomenon, Spring-embedded shoulder protection packer rubber cylinder can limit the flow of rubber material, so in the downhole temperature above 150℃ environment, spring shoulder packer rubber can be used to prevent the flow of rubber material and prevent the shoulder process phenomenon. However, because the spring and the metal mesh are metal materials, when the spring, the metal mesh and the rubber cylinder are compressed together, the inside of the rubber cylinder may tear, affecting the sealing performance of the rubber cylinder. Therefore, rubber and metal materials with appropriate hardness should be selected during the design process to avoid seal failure caused by internal tearing.
Point 7: What are the next steps in this research? Are there any planned experimental validations or further optimization studies for the design?
Response 7: Subsequent experiments will be carried out to further optimize the finite element model. In addition, a three-dimensional finite element model of the spring shoulder casing will be established in the future to refine the material parameters of the spring and the metal, and to clarify the contact relationship between the spring, the metal mesh and the rubber casing, so that the finite element model can more accurately restore the real working conditions.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThanks for the invitation to review this work. Traditional packer rubber cylinders fail in high-temperature and high-pressure environments due to deterioration, leading to sealing failures. The study proposes a new design for a spring-embedded shoulder protection packer rubber cylinder, combining metal and rubber to enhance sealing performance. The spring-embedded shoulder protection packer rubber cylinder offers improved sealing performance and service life in high-temperature and high-pressure environments. However, relative design comparisons and specific measurements should be further detailed for clarity.
1) How does the composite material (metal and rubber) in the proposed design specifically contribute to improved performance compared to other composite materials that have been tested? Consider citing Chem 10 (2024) 1638-1640 for background discussion on the relative roles of metal and rubber.
2) The study focuses on 25°C and 177°C. How does the new design perform at intermediate temperatures or in scenarios with rapid temperature fluctuations?
3) How does the proposed design compare with other recent advancements in packer rubber cylinder technology, particularly those focusing on different structural enhancements or material compositions?
4) The study mentions improvements in compression distance, Mises stress, and sealing performance coefficient. Can the authors explain the rationale behind choosing these specific metrics and how they comprehensively capture the performance improvements of the new design?
5) How were the percentages for compression distance reduction, Mises stress reduction, and sealing performance coefficient increase calculated? Are there detailed numerical data supporting these percentage changes?
6) What specific measurements or observations were used to confirm that the spring-embedded protective rubber cylinder does not experience shoulder protrusion?
Comments on the Quality of English LanguageIn the abstract, "The current trend in oil extraction is shifting towards high-temperature and high-pressure environments, which leads to the deterioration of the rubber material used in the packer rubber cylinder, ultimately resulting in sealing failure." is confusing (mixing challenges and trends).
In the introduction, " solutions to the issue of" this seems not standard english.
Author Response
Response to Reviewer 3 Comments
Thank you for your comments and suggestions on the manuscript. They are valuable for us to improve the written quality of the currently work and give guidance for the future work. Your queries are answered one by one as follows.
Point 1: How does the composite material (metal and rubber) in the proposed design specifically contribute to improved performance compared to other composite materials that have been tested? Consider citing Chem 10 (2024) 1638-1640 for background discussion on the relative roles of metal and rubber.
Response 1 The metal mesh, spring and rubber material are vulcanized. The structural design focuses on the spring and the metal mesh. The purpose of introducing the spring is to prevent the shoulder protruding after the spring is pulled apart during the setting of the packer rubber cylinder, and at the same time limit the flow of the rubber cylinder. The role of the metal mesh is to wrap the rubber cylinder when the rubber cylinder is set in a high temperature environment and prevent the flow of the rubber material. Thanks for the literature recommended by the reviewers, the literature has been added to the citation, citation number 23.
Point 2: The study focuses on 25°C and 177°C. How does the new design perform at intermediate temperatures or in scenarios with rapid temperature fluctuations?
Response 2:We did not do a spring shoulder packer cartridge finite element analysis at moderate temperatures. According to the finite element analysis at 25℃ and 177℃, the performance of the two types of packer tubes at 25℃ is the same, and the performance of the spring shoulder packer tubes at 177℃ is better than that of the traditional packer tubes. Therefore, it is speculated that the performance of the spring shoulder packer tubes is better than that of the traditional packer tubes at the medium temperature range. According to literature research[1], the fluctuation range of downhole temperature at high temperature is small, and the fluctuation speed is slow. Therefore, the influence of rapid temperature fluctuation on the sealing performance of spring shoulder packer rubber barrel is not considered.
[1]Xuefeng Z. Successful application of ceramic rupture arch valve in high-temperature and high-pressure gas wells[J]. Petrochemical Technology, 2023, 30(3):60-62.
Point 3: How does the proposed design compare with other recent advancements in packer rubber cylinder technology, particularly those focusing on different structural enhancements or material compositions?
Response 3: In order to improve the sealing performance of high-temperature downhole packer, many scholars have improved the structure of packer casing. Some scholars combine the ring and rubber on the shoulder for vulcanization processing to prevent the shoulder process, but the ring does not have resilience, which causes inconvenience in the recycling of the rubber cylinder. The spring has resilience, and the ring is changed into a spring. When the rubber cylinder is recycled, the resilience makes the rubber cylinder shrink rapidly and improves the recovery efficiency.
Point 4: The study mentions improvements in compression distance, Mises stress, and sealing performance coefficient. Can the authors explain the rationale behind choosing these specific metrics and how they comprehensively capture the performance improvements of the new design?
Response 4: The compression distance is the axial displacement of the upper spacer ring when the packer casing is set. The compression distance decreases and the contact line length of the casing increases, which can improve the sealing performance of the casing. Mises stress is also called the maximum energy failure criterion or distortion energy theory, which is based on the concept of strain energy density in elasticity. Mises stress is calculated to evaluate under what conditions seal failure will occur inside the rubber cylinder. Mises stress is evenly distributed inside the rubber cylinder, indicating that the gelatin cylinder will not fail due to stress concentration. The sealing performance coefficient is the product of the contact stress between the casing and the casing and the length of the contact line. Both the contact stress and the contact line length are important parameters for evaluating the sealing performance of the packer's rubber cylinder. The greater the contact stress and the longer the contact line length, the greater the sealing performance coefficient, which proves the better the sealing performance of the rubber cylinder.
Point 5: How were the percentages for compression distance reduction, Mises stress reduction, and sealing performance coefficient increase calculated? Are there detailed numerical data supporting these percentage changes?
Response 5: The compression distance reduction is analyzed according to the cloud image of the axial compression distance of the rubber cylinder. The maximum value on the cloud image is the axial compression distance
The percentage reduction of compression distance is calculated as follows:
Where: ——percentage of compression distance;
——Traditional packer cartridge compression distance, mm;
——spring shoulder packer cartridge compression distance, mm
In this formula, the compression distance of the traditional packer casing at high temperature is =46.85mm, and the compression distance of the spring shoulder packer casing is =45.46. According to the above formula, the compression distance reduction percentage =3% is obtained.
Mises stress is used to extract data from cloud images, and the Mises stress reduction percentage is calculated as follows:
Where: ——Mises stress reduction percentage;
——The maximum Mises stress of conventional packer cartridge, MPa;
——the maximum Mises stress of spring shoulder packer cartridge, MPa.
The maximum Mises stress of traditional packer casing at high temperature was 37.58MPa, and the maximum Mises stress of spring shoulder packer casing was 32.68MPa, and the maximum Mises stress reduction =14% was obtained according to the above formula.
The sealing performance coefficient reduced by K percentage is calculated as follows:
Where: ——sealing performance factor K increases by percentage
——Sealing performance coefficient of spring shoulder packer rubber casing;
——Sealing performance coefficient of traditional packer cartridge.
At 25℃,The sealing performance coefficient =371.7, and the sealing performance coefficient =362.96. According to the above formula, the sealing performance coefficient increase percentage =2. At 177℃,The sealing performance coefficient =371.7 for spring shoulder packer and =510.72 for traditional packer. The sealing performance coefficient increase percentage =11% was obtained according to the above formula. The calculation methods and data on the percentage reduction of compression distance, the percentage reduction of maximum Mises stress and the percentage increase of sealing factor have been added to the paper.
Point 6: What specific measurements or observations were used to confirm that the spring-embedded protective rubber cylinder does not experience shoulder protrusion?
Response 6 First, through analyzing the Mises stress cloud map of the rubber barrel, the results showed that the stress in the side rubber barrel of the spring shoulder packer was concentrated at the position of the spring and the metal mesh, and there was no stress concentration in the rubber barrel, while there was stress concentration in the traditional rubber barrel at the shoulder and shoulder protrusion phenomenon. Secondly, the shoulder spike value is introduced, which is restored in equal proportion after measurement on the packer casing. It is found that the shoulder spike value of the spring shoulder packer casing is 0 during setting, while the shoulder spike value of the traditional packer casing is greater than 0 regardless of 25℃ and 177℃, indicating that the shoulder spike will not occur in the spring shoulder packer casing.
Point 7: In the abstract, "The current trend in oil extraction is shifting towards high-temperature and high-pressure environments, which leads to the deterioration of the rubber material used in the packer rubber cylinder, ultimately resulting in sealing failure." is confusing (mixing challenges and trends).
In the introduction, " solutions to the issue of" this seems not standard English.
Response 7: The expression of line1~line3 has been modified. Introduction (line12) revises "issue" to "problems".
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have incorported some changes based on the suggestions provided by the reviewer. It would have been better if the authors could have incoprprated the meshing details
Comments on the Quality of English LanguageMinor prooof reading needed
Author Response
Thank you for your comments and suggestions on the manuscript. They are of great importance for us to improve the written quality of the currently work and give guidance for the future work. Your queries are answered one by one as follows.
Point 1: The authors have incorported some changes based on the suggestions provided by the reviewer. It would have been better if the authors could have incoprprated the meshing details
Response 1: Thanks for the reviewer's comments, the content of grid division has been optimized and added into the paper.
Point 2: Minor proof reading needed
Response 2: Thanks for the reviewer's suggestions, the improper wording in the article has been revised.
Reviewer 3 Report
Comments and Suggestions for AuthorsThanks for the invitation to review this article. The authors have addressed the concerns, and I recommend the article for publication. However, a few minor errors should be proofread and corrected before final publication.
In introduction, “Zhang Fuying et al conduct” should revise “conducted”
"Designing a multi-layer tensile spring at the ends of the upper and lower rubber cylinders to enable the rubber cylinder to withstand significant annular pressure differences during operation." is short of verb.
“…is subjected to finite element analysis using ABAQUS software." The word, “is subjected to” in this sentence is confusing.
Comments on the Quality of English Language
Thanks for the invitation to review this article. The authors have addressed the concerns, and I recommend the article for publication. However, a few minor errors should be proofread and corrected before final publication.
In introduction, “Zhang Fuying et al conduct” should revise “conducted”
"Designing a multi-layer tensile spring at the ends of the upper and lower rubber cylinders to enable the rubber cylinder to withstand significant annular pressure differences during operation." is short of verb.
“…is subjected to finite element analysis using ABAQUS software." The word, “is subjected to” in this sentence is confusing.
Author Response
Thank you for your comments and suggestions on the manuscript. They are valuable for us to improve the written quality of the currently work and give guidance for the future work. Your queries are answered one by one as follows.
Point 1: In introduction, “Zhang Fuying et al conduct” should revise “conducted”
Response 1: Thanks for the reviewer's writing suggestions, which have been modified in the original text.
Point 2: "Designing a multi-layer tensile spring at the ends of the upper and lower rubber cylinders to enable the rubber cylinder to withstand significant annular pressure differences during operation." is short of verb.
Response 2: Thanks to the reviewer's suggestion, the verb has been added into the sentence.
Point 3: “…is subject to finite element analysis using ABAQUS software." The word, “is subjected to” in this sentence is confusing.
Response 3: Thanks to the reviewer's suggestion, the inaccurate description in the article "is subjected to finite element analysis using ABAQUS software" has been revised.
