Study of Wettability Alteration of Hydrophobic Carbonate Rock by Surfactant-Containing Chelating Agent Solutions
Round 1
Reviewer 1 Report
The authors report the “Study of wettability alteration of hydrophobic carbonate rock by surfactant-containing chelating agent solutions.” This paper investigates the interfacial processes at the surface of hydrophobic rocks in the presence of EDTA-based chelating agents and different classes of surfactants, as well as the wettability changes of model hydrophobic rocks under conditions specific to oil well stimulation. After evaluating this manuscript, I think this article is fine with minor revisions before publication. My comments are as follows:
1. In the Abstract, in line 20, the author proposes “CA”, and the author should explain in advance what it refers to specifically.
2. Part 3.2, line 298, the author said, "The contact angle of hydrophobized Iceland spar slices values lay in the range of 85-115°, which, again, indicated successful hydrophobization." The water contact angle greater than 90° is hydrophobic, the author It is not very reasonable to write 85-115°.
3. The labeling content in Figure 5 and Figure 6 is not clear, and the error bars in Figure 6 are not obvious enough. It is suggested that the author adjust it.
4. The author studied the effect of adding different surfactants, why didn't the samples be analyzed by SEM?
5. In section 3.3, the author only shows Caverns, formed by plain CA at 120°C, and the author can also show it under other conditions for comparison.
6. In addition, the authors are suggested to design a simple experimental setup to simulate practical applications to increase convincing power.
7. Finally, the conclusion should not only describe the intuitive phenomenon, but the word count of the conclusion is lengthy, and the author is advised to refine the sentence appropriately.
Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
This paper studies the wettability alteration of hydrophobic carbonate rock by surfactant-containing chelating agent solutions. It's objecti is clear and the text is well organized. I think it can be accepted for publication.
Author Response
We thank you for the time and efforts that you devoted for reviewing our paper.
Reviewer 3 Report
The paper studied cationic, amphoteric, and anionic surfactants in the absence and presence of the CA, as well as the CA alone aiming to to explore the wettability alteration of hydrophobic carbonate rock by surfactant-containing CA-based fluids. It is well written. Here are my comments:
Figure 7 is described the mechanism controling wettability alteration. It is a bit difficult to understand. Please describe more about the mechanism.
The English writing is good
Author Response
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Author Response File: Author Response.docx
Reviewer 4 Report
The authors study wettability alteration in hydrophobic carbonate rock samples due to their exposure to chelating agent and different surfactant classes. They carefully examine changes in wettability on the surface of the rock samples. They report wettability alterations at two different temperatures and a synergy between the chelating agent and the surfactants. They also discuss the potential responsible mechanisms for the observed behavior.
The paper is very well written and does an excellent job of motivating the work, describing the experiments, and discussing the results.
I have one minor suggestion, otherwise, I recommend the publication of the paper.
The plots in Figure 6 are rather difficult to read. I would advise redoing these figures using larger fonts. Also, the y-axis appears to be in Russian. I would recommend changing these to English to make the content accessible to a wider audience.
Author Response
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Author Response File: Author Response.docx
