Dynamic Criteria for Physical Modeling of Oil Displacement by Gas Injection
Round 1
Reviewer 1 Report
The manuscript studies the lab-scale gas-enahnced oil recovery, for which a new parameter, the flow rate ratio, to characterise the process and determine the minimum miscibility pressure. The new parameter may provide new understanding to the process. However, the current version has the following major issues:
1. The significance of the new parameter is not clear. The authors didn't show in which condition the new parameter is better than other ones listed in the literature. Some detailed comparisons can be added.
2. There is not enough theoretical analysis of the new parameter. Although FRR changes are accompanied by changes of other parameters, they are from a few experiments and sometimes the correlation is not clear. The discussion on the mechanism is limited.
3. The presentation should be improved. There are many abbreviations, many have no definitions. The format of some equations is not standard. The models in the tables are not cited or explained. Values like "12,5 Mpa".
Author Response
Dear Reviewer
1, 2) New calculation results have been added. The significance of the new parameter for clarifying the value of the minimum miscibility pressure MMP is shown.
3) Abbreviations have been added to the text.
Thank you for your comments which were very helpful to us
In order to more clearly reveal the essence of our research, we carried out serious additional calculations and showed that the proposed flow rater ratio (FRR) parameter based on displacement dynamics helps to more accurately estimate the value of the minimum miscibility pressure MMP.
All new data has been added to the article, and we hope that this version of the article fully reflects the significance and results of the study.
We hope for your feedback.
Sincerely yours Alexey Sorokin
Reviewer 2 Report
In this work, a new dynamic criterion -- APP parameter is used to determine the displacement mode in the early filtration stage. Like other criterions (such as ORF, GOR, GBP, etc.), this new criterion can be used for feasibility study of gas injection. This is somewhat innovative.
1、Please identify the specific meaning of "BPR" in the manuscript.
2、It seems that the “2” in “CO2” in the manuscript should be subscript.
3、The name of Figure 2 is a little too simplified, I suggest more clarity.
4、In the above paragraph of Table 1, "according to the correlation equations for CO2", please add references or indicate specific contents.
5、If the data in Table 1 is calculated with reference to other people's data, please add references.
6、It is suggested that the third part (Results and Discussion) of the paper be divided into two sections for analysis and discussion.
7、In the following paragraph of Figure 5, why did the displacement intensity and overall recovery of the dynamics of FRR values for APG injection are higher than that of CO2? It can be analyzed and expounded in the paper.
Author Response
Dear Reviewer
1) Back pressure regulator (BPR) the transcript was added to the description of the Figure
2-5, 7) Some of the data related to these items has been replaced with new ones
6) Perhaps in this version it is better to combine the results and discussion for a better understanding of the results
Thank you for your comments which were very helpful to us
In order to more clearly reveal the essence of our research, we carried out serious additional calculations and showed that the proposed flow rater ratio (FRR) parameter based on displacement dynamics helps to more accurately estimate the value of the minimum miscibility pressure MMP.
All new data has been added to the article, and we hope that this version of the article fully reflects the significance and results of the study.
We hope for your feedback.
Sincerely yours Alexey Sorokin
Round 2
Reviewer 1 Report
The revised manuscript has addressed the previous comments. Just some minor spell check is required.
Author Response
Dear Reviewer
Thank you for your comments
As you indicated, minor changes were made in the text, such as misprints, numbering of figures and names of figures
