Case Study: Successful Application of a Novel Gas Lift Valve in Low Pressure Wells in Fuling Shale Gas Field
Round 1
Reviewer 1 Report
The review of the manuscript entitled: “Case Study: Successful Application of a Novel Gas Lift Valve in Low Pressure Wells in Fuling Shale Gas Field”. In this manuscript, a newly designed type of gas lift valve that is very sensitive to low pressure was successfully applied. By responding to the following comments and questions, the work can be recommended for publication:
1. Abstract: in this section, the authors mention that their application was successful, but, how? On which basis? How did they develop or design? More details should be added.
2. The Introduction section needs to be extended by describing the cause, fatality, novelty of the work, advantages, and disadvantages of the present study.
3. It is recommended to add a sentence about other methods of production under high-pressure, high-temperature conditions. The next reference can be used in the revision stage: (SPE-174277-MS, 2015, Prevention of Calcium Carbonate Precipitation during Water Injection into High-Pressure High-Temperature Wells)
4. The English language should be completely checked. There are some mistakes.
5. Quality of the new apparatus (fig 4) should be improved. Again, more description of this apparatus is vital.
6. The results should be deeply discussed. This is a scientific paper and not a report.
7. It is recommended to add the analysis of variance (ANOVA). If is it impossible in the revision stage, please mention it as a suggestion for future work. The next work can be used in the revision stage: (Optimization of the demulsification of water-in-heavy crude oil emulsions using response surface methodology, Fuel, 2022, 124270).
8. On which basis the values of kick-off pressure or operating pressure were selected?
9. The authors state: “A total of 13 wells were assembled with gas lift valves and 8 of them were operated successfully, the total incremental of gas rate is 7684.5Mscf/d with total lifted liquid volume of 659.6bbl”, the reason for the failure in other 5 wells?
10. The conclusion also needs to be rewritten. Include the following: new concepts and innovations demonstrated in this study, a summary of findings, a comparison with findings by other workers, and a concluding remark.
11. Please use more references.
Author Response
The review of the manuscript entitled: “Case Study: Successful Application of a Novel Gas Lift Valve in Low Pressure Wells in Fuling Shale Gas Field”. In this manuscript, a newly designed type of gas lift valve that is very sensitive to low pressure was successfully applied. By responding to the following comments and questions, the work can be recommended for publication:
- Abstract: in this section, the authors mention that their application was successful, but, how? On which basis? How did they develop or design? More details should be added.
Answer: The updated manusript is uploaded for your reference. Thanks for your comments. The successful application of the new type of gas lift valve in the field mostly due to: (1) the gas lift valve can be open/close at low valve dome pressure which indicates the high sensitivity to low production pressure. Thus, the piping line pressure can be utilized to activate the valve due to its new advantages. Field application result shows that all wells were successfully restarted by only using the piping line pressure. (2) A special designed structure of gas lift valve can be activated via pressure increasement in tubing, and a channel was created between tubing and annulus. The valve which is used as dummy valve then switched to gas lift valve. Thus, fewer slickline operations were conducted due to its new features. The abstract section was revised based on the comments, please refer to it.
- The Introduction section needs to be extended by describing the cause, fatality, novelty of the work, advantages, and disadvantages of the present study.
Answer: The cause, fatality, novelty of the work together with the advantages has been added/recomposed in introduction section, please refer to it.
- It is recommended to add a sentence about other methods of production under high-pressure, high-temperature conditions. The next reference can be used in the revision stage: (SPE-174277-MS, 2015, Prevention of Calcium Carbonate Precipitation during Water Injection into High-Pressure High-Temperature Wells)
Answer: Thanks for the good advice. One sentence is added in paragraph 2 of introduction, which is “Studies also shows that there might be flow assurance issue, e.g., salt precipitation, of wells produce under high pressure and high temperature [6]”. Please refer to introduction part.
- The English language should be completely checked. There are some mistakes.
Answer: Thanks for the good advice. The English phrases have been completely checked. Please refer to the updated paper.
- Quality of the new apparatus (fig 4) should be improved. Again, more description of this apparatus is vital.
Answer: Figure 4 of the new apparatus has been improved. More description also added to part 2: Gas Lift Valves. Please refer to the updated first paragraph of part 2.
- The results should be deeply discussed. This is a scientific paper and not a report.
Answer: The conclusion has been deeply discussed as can be found in conclusion part.
- It is recommended to add the analysis of variance (ANOVA). If is it impossible in the revision stage, please mention it as a suggestion for future work. The next work can be used in the revision stage: (Optimization of the demulsification of water-in-heavy crude oil emulsions using response surface methodology, Fuel, 2022, 124270).
Answer: Thanks for your good suggestion. Due to the limited well cases, the analysis of variance (ANOVA) seems not practical at current stage. But in the future the ANOVA should be conducted to see the application range of piping line pressure. Thus, we will have an quantitative application in other wells.
- On which basis the values of kick-off pressure or operating pressure were selected?
Answer: The kick-off pressure was selected based on the average piping pressure of the gas field. In traditional gas lift wells, the operating pressure should be decided as to continuously lift the liquid. But in this paper, the gas lift valve is only be used to lift the well once and leave the well to produce by its own energy.
- The authors state: “A total of 13 wells were assembled with gas lift valves and 8 of them were operated successfully, the total incremental of gas rate is 7684.5Mscf/d with total lifted liquid volume of 659.6bbl”, the reason for the failure in other 5 wells?
Answer: Thanks for the note. The author was trying to convey the idea that 8 wells were operated successfully, and the rest were waiting to be operated in future. So, we added one sentence in page 9 that is “The rest were waiting to be operated once the equipment is ready.”. Please refer to the paper.
- The conclusion also needs to be rewritten. Include the following: new concepts and innovations demonstrated in this study, a summary of findings, a comparison with findings by other workers, and a concluding remark.
Answer: the conclusion has been rewritten. Please refer to the conclusion part.
- Please use more references.
Answer: thanks for the good suggestion. More references have been added as the background of field introduction. Please refer to the References part.
Submission Date
26 October 2022
Date of this review
04 Nov 2022 06:47:38
Reviewer 2 Report
The authors published the newly designed type of gas lift valve. It's characterizing improved sensitive to low pressure was successfully applied in this field in the piping line sufficient pressure is to lift the loaded liquid in tubing. Besides the authors presented the special designed structure which can be utilized to activate the valve and can reduce the operations frequency. Thus, the operation risks will be significantly reduced. The new type of gas lift system can provide a wide range of application prospects for low pressure wells, especially for shale gas wells.
The paper contains cardinal errors and, in its current form, requires deep revisions
Strong
Good topic.
Weak
If the authors think that it is possible to publish a paper on a new valve without a clear drawing, they are hugely mistaken. This is the biggest weakness of the paper.
The second major weakness is the listing of units outside the Si system. This is unacceptable.
Noticed errors/remarks
• Lack the number of lines
• Units: bbl/d, ft, BCF, psi and more for sure are not units of SI system. They may be popular in offshore technology and in the US, but they are unacceptable in scientific papers. They should be corrected/converted to legal SI units.
• The analysis of the status of the issue is presented in residual form. There is no summary of the status of the issue and no clear identification of the research gap.
• Figure 4. is almost not too readable (poor quality). The author must improve or delete it.
• Figure 10. Illegible axes (truncated) at red line sub chart. This should be corrected.
• The conclusions are extremely poor. For 9 pages of text, the authors made less than 6 lines of conclusions. This is a bit frivolous for a paper for a reputable journal. No conclusions for further research.
• The list of literature sources has only 7 items. This is not even enough for a conference paper. For a well-known journal, it is definitely not enough.
Small errors
• Put a space between the value and the unit. This applies to the entire work.
• Page 3. Is: China(Figure 5); should be: China (Figure 5). These errors type should be corrected throughout the paper.
Author Response
The authors published the newly designed type of gas lift valve. It's characterizing improved sensitive to low pressure was successfully applied in this field in the piping line sufficient pressure is to lift the loaded liquid in tubing. Besides the authors presented the special designed structure which can be utilized to activate the valve and can reduce the operations frequency. Thus, the operation risks will be significantly reduced. The new type of gas lift system can provide a wide range of application prospects for low pressure wells, especially for shale gas wells.
The paper contains cardinal errors and, in its current form, requires deep revisions
Strong
Good topic.
Weak
If the authors think that it is possible to publish a paper on a new valve without a clear drawing, they are hugely mistaken. This is the biggest weakness of the paper.
Answer: The updated manuscript is uploaded for your reference. Thanks for your good comments. To depict the basic function of the new type of gas lift valve, a clearer drawing has been updated. And some descriptions are added in the first paragraph of section 2. Please refer to the corresponding part.
The second major weakness is the listing of units outside the Si system. This is unacceptable.
Noticed errors/remarks
- Lack the number of lines
Answer: the format refers to a fixed template, so I am not sure I can add the number of lines. Please can the editor help to clarify it.
- Units: bbl/d, ft, BCF, psi and more for sure are not units of SI system. They may be popular in offshore technology and in the US, but they are unacceptable in scientific papers. They should be corrected/converted to legal SI units.
Answer: thanks for your good suggestions. All unit has been corrected to SI system. Please refer to paper.
- The analysis of the status of the issue is presented in residual form. There is no summary of the status of the issue and no clear identification of the research gap.
Answer: Thanks for the advice. We add some sentences to describe the issue status. Please refer to the second paragraph of updated manustript.
- Figure 4. is almost not too readable (poor quality). The author must improve or delete it.
Answer: Thanks for your good suggestion. Figure 4 has been updated as can be found in paper. The quality of the figure is improved, and more descriptions were added to illustrate the fundamental function of the new gas lift valve.
- Figure 10. Illegible axes (truncated) at red line sub chart. This should be corrected.
Answer: The chart has been updated, please refer to the paper.
- The conclusions are extremely poor. For 9 pages of text, the authors made less than 6 lines of conclusions. This is a bit frivolous for a paper for a reputable journal. No conclusions for further research.
Answer: the conclusion has been rewritten and more discussion is added to this part.
- The list of literature sources has only 7 items. This is not even enough for a conference paper. For a well-known journal, it is definitely not enough.
Answer: more reference papers are added to the reference part. Please refer to it.
Small errors
- Put a space between the value and the unit. This applies to the entire work.
Answer: thanks for the suggestion. All errors are corrected.
- Page 3. Is: China(Figure 5); should be: China (Figure 5). These errors type should be corrected throughout the paper.
Answer: thanks for the suggestion. All errors are corrected.
Submission Date
26 October 2022
Date of this review
09 Nov 2022 15:48:35
Round 2
Reviewer 1 Report
The work is ready for publication.
Reviewer 2 Report
The authors have corrected all the errors I noticed to an appropriate degree. Thus, the obstacles to the publication of this paper have ceased.
