Prediction of Longitudinal Superimposed “Sweet Spot” of Tight Gas Reservoir: A Case Study of Block G, Canada

Round 1

Reviewer 1 Report

-

Author Response

You have not given specific comments. I have made modifications according to the requirements of other reviewers.

Reviewer 2 Report

The main arguments of the paper follow the current thinking. The paper aims to study the prediction of longitudinal superimposed areas favorable for enrichment of tight gas reservoirs, using a case study of a block in Canada.

More than 80% of references belong to the last decade. The extent of the article should be increased and supported on a higher number of references. Considering that less than 25% of references are from authors living in other continents than Asia, the authors of this paper should tackle this reviewer comment.   

The results should be also commented considering the contribution of new references to the discussion.

The written English of this work could be revised in order to improve the clarity of several sentences of the text.

Key findings of the article could be better explained and supported on more data.

Once the authors tackled the following reviewer comments, the reviewer can recommend this paper for publication:

Line 73, The meaning of MIC should be given.

Line 87, Please revise altitude considering - 1040 m- 2720 m.

Line 98, the meaning of GR should be given.

Line 95, International classification(s) of sedimentary rocks should be given to support the classification of fine sandstone based only on particles size-range of 20-50 μm, as reported by authors.

Line 100, Reference [21] was not found by the reviewer in the journal indicated.

Line 104, Logs of Fig. 1 are blurred. Legends and curves should be better shown for the sake of an easy reading.

Line 169, The reviewer did not find the meaning of RI in the manuscript.

Lines 183-190, These results could be better commented regarding the data scattering.

Lines 190 and 200, References of data shown in Figs. 2 and 3 should be given, also considering its initial publication.

Lines 195-200, These results could be better commented regarding the data scattering.

Lines 275-285, The reasons for considering the results of layer E and of other layers of Upper and Lower Series should be given although only the results of layer E are reported as statistically significant. Why do the authors report a case study for the prediction of “sweet spots” where the layers with lower statistically significant results are prevailing?

The answers to major reviewer comments should considered in Abstract and Conclusions section.

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

O artigo contém muitos erros ortográficos, está difícil de compreender algumas etapas, precisa de mais detalhes nas considerações finais, resumo e introdução.

Author Response

Some written English have been revised.

Reviewer 4 Report

This paper presents an ML model for predicting the sweet spot in reservoirs. The paper is written in a very confusing way. I can see that the authors have produced some 2D map while we expect to use log data and estimate where in the well the sweet spots are. I suggest the authors to check this paper (https://doi.org/10.1016/j.eswa.2017.07.015) and reorganize the paper based on this since it is one of the primary works for sweet spot and it offers a great workflow.

I can review the paper after this revision.

Author Response

"Data mining and machine learning for identifying sweet spots in share reserves" is a very good article and I have listed it as reference. But the idea of this article is to provide a new workflow. At present, the prediction of "sweet spot" is generally based on geological re-search without considering the factors of productivity. Based on the existing Petrel work area, this paper uses mathematical methods to further depict the favorable area. This method saves cost, has been applied in practical production, and is effective. I really hope to get your affirmation.

Round 2

Reviewer 2 Report

In the revised manuscript there are issues still needing to be solved:

Line 95 of the former manuscript, Based on Udden-Wentworth scale, sand fraction does not have particle size values of 20-50 μm. This comment should be better answered: the range of particles size of sandstones should be given.

An international classification for sandstone rocks could be given and not only for sand particles. Journal references also could be given.

Line 104 of the former manuscript, Logs of Fig. 1 are still blurred.

Lines 190 and 200 of the former manuscript, The reviewer did not find in the revised manuscript the asked References of data shown in Figs. 2 and 3.

Lines 275-285 of the former manuscript, The reviewer did not find in the revised manuscript any answer to one of the reviewer's major comments .

Line 71 of the revised manuscript, Consider Heege et al. and not Jan et al.

Please revise the text in order to avoid similar written sentences to cited articles.

 

Author Response

Please see the attachment.

Author Response File: Author Response.doc

Reviewer 4 Report

The paper can be published.

Author Response

Thanks for your approval!