Accumulation Conditions and Pattern of Tight Oil in the Lower Submember of the Fourth Member of the Shahejie Formation in the Damintun Sag, Bohai Bay Basin

Round 1

Reviewer 1 Report

I have completed the evaluation of ms under reference. The work has been meticulously conducted presented in a concise manner. I have a few suggestions as regards the presentation.

1. The abstract is too descriptive. In my opinion, authors should provide information related to their findings/results.

2. Another concern is about the details about the methods used; FE-SEM/ confocal SEM etc., Authors are advised to provide details of the methodology adopted/followed for the study.

3. Figures are not of good quality. these should be improved.

4. Add details about the magnification in the micrographs.

5. Authors need to take care of repetitive phrases in the sentences at several places in the ms.; e.g. 'tight oil' has been used three to four times in a single sentence at several places.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The aim of this paper is to present accumulation conditions and pattern of tight oil in the lower submember of the fourth member of the Shahejie Formation in the damintun sag, Bohai bay basin. The target horizons of this study are the oil shales in the fourth member of the Shahejie Formation (E2S42), which have always been considered source rocks.  In this study, 40 oil shale samples were collected from the E2S42 at several key exploration wells.

The research design is appropriate. The title of the paper reflects its content. But the first thing that comes to mind - abstract looks like conclusions. I recommend writing in the abstract the main goal of the study.

 The document must be checked as there are some inaccuracies and style errors. e.g.:

Different citation styles

26. Hubert F, Caner L, Meunier A, et al. Unraveling complex<2μm clay mineralogy from soils using X-ray diffraction profile mod-eling on particle-size sub-fractions:Implications for soil pedogenesis and reactivity[J].American Mineralogist, 2012, 97 (2-3) :384-398.

27. JIAO Shujing,ZHANG Hui,XUE Dongchuan,et al.Morphological structure and identify method of organic macerals of shale with SEM[J].Journal of Chinese Electron Microscopy Society,2018,37(2):137-144.

Figure 1. Part of the text is unreadable. Wrong font and sizes selected.

Figure 5. Title is too long. I recommend to move part of the text (e.g. pore diameter, depth) to the main body

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

This paper is focused on geological analysis of tight oil formation. I suggest the following revisions:

 

(1) Figure 3: what is the criteria of dividing regions? Please indicate it in the paper.

(2) Figure 7b is not clear. Please make sure audience can read your axis.

(3) Could you explain why Bed 2 has lower OM abundance? Please also highlight it in the conclusion part.

(4) For the permeability of tight rocks, we generally use gas apparent permeability. Please refer to the following paper to give a brief introduction to make sure audience understands it:

On the flow regime model for fast estimation of tight sandstone gas apparent permeability in high-pressure reservoirs

(5) For the oil accumulation pattern, I suggest the authors to combine with previous study in this area, and show their key innovation point. This part is very important as it is hilighted in the topic. But I did not see some comparisions with previous studies.

 

 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Good to go.