Overpressure: Origin, Prediction, and Its Impact in the Xihu Sag, Eastern China Sea
Round 1
Reviewer 1 Report
The manuscript makes an excellent impression, is written in good scientific language and is a complete serious study. In the Introduction, the authors provide a detailed review, the authors provide relevant and up-to-date information on the state of research. In the “Samples and Methods” section the analytical methods are fully described, the “Results and Discussion” are detailed. The Discussion and Conclusion reflect the main results of the research and fully reveal the intention and results of the future article. The abundance of figures helps to better understand the information and enhances the impression of the manuscript.
In general, the manuscript is suitable for publication in a journal. In my opinion the manuscript can be published after the error correction and careful checking references. It is also necessary to correct the manuscript according to journal requirements.
My comments are listed below:
- Check all references to literature and arrange them in accordance with the requirements of the journal.
- Almost all references (21 out of 28) are given in the Introduction. In the Discussion section, it is desirable to add 5-10 references to modern articles.
Correct the manuscript according to journal requirements.
Author Response
Replies to Reviewers
First of all, we thank both the reviewers and editor for their thorough and valuable review, as well as constructive comments and fruitful suggestions, which have contributed in improving the quality of the paper.
Some literatures according to reviewers' requirements have been supplemented to the reference section, including:
[22] Shen W F, Yu Z K, Diao H, et al. Simulation of heat flow evolution history in Xihu sagand its significance for hydrocarbon accumulation[J]. China Offshore Oil Gas, 2020, 32(1): 42-53. DOI: 11935/j.issn.1673-1506.2020.01.005.
[23] Jiang Y M, Zou W, Liu J S, Tang X J, He, X J. Genetic Mechanism of Inversion Anticline Structure at the End of Miocene in Xihu Sag, East China Sea: A New Understanding of Basement Structure Difference[j].Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences45(3):968. DOI: 3799/dqkx.2019.292.
[30] Wang Y, Chen J, Pang X, et al. Hydrocarbon generation and expulsion of tertiary coaly source rocks and hydrocarbon accumulation in the Xihu Sag of the East China Sea Shelf Basin, China[J]. Journal of Asian Earth Sciences, 2022: 105170.DOI: 10.1016/j.jseaes.2022.105170.
[31] Ye J, Qing H, Bend S L, et al. Petroleum systems in the offshore Xihu Basin on the continental shelf of the East China Sea[J]. AAPG bulletin, 2007, 91(8): 1167-1188. DOI: 10.1306/02220705158.
[32] Su A, Chen H, Lei M, et al. Paleo-pressure evolution and its origin in the Pinghu slope belt of the Xihu Depression, East China Sea Basin[J]. Marine and Petroleum Geology, 2019, 107: 198-213.DOI: 10.1016/j.marpetgeo.2019.05.017.
[33] Wang F, Chen D, Wang Q, et al. Quantitative evaluation of caprock sealing controlled by fault activity and hydrocarbon accumulation response: K gasfield in the Xihu Depression, East China Sea Basin[J]. Marine and Petroleum Geology, 2021, 134: 105352.DOI: 10.1016/j.marpetgeo.2021.105352.
[35] Wang W, Lin C, Zhang X, et al. Provenance, clastic composition and their impact on diagenesis: A case study of the Oligocene sandstone in the Xihu sag, East China Sea Basin[J]. Marine and Petroleum Geology, 2021, 126: 104890. DO I: 10.1016/j.marpetgeo.2020.104890.
[36] Wang W, Lin C, Zhang X, et al. Effect of burial history on diagenetic and reservoir-forming process of the Oligocene sandstone in Xihu sag, East China Sea Basin[J]. Marine and Petroleum Geology, 2020, 112: 104034. DOI: 10.1016/j.marpetgeo.2019.104034.
For the reviewer's suggestion, we have made changes to the manuscript. A revised manuscript ( .docx) with revisions mode is also submitted. We believe that the revised manuscript fully resolved the reviewer's concerns and hope it would be suitable for publication in Energies.
Sincerely yours,
Ruizhao Yang
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript reports the origin, prediction and petrophysical effects of overpressure in the Xihu Sag in the East China Sea Basin. Detailed studies on the evolution and origin of pressure are presented providing the analysis of the influence of overpressure on porosity and permeability in the reservoir. The results reported represent a notable advance in the understanding of how overpressure influences the porosity and permeability in the hydrocarbon reservoir.
The title and abstract are appropriate for the content of the text. Furthermore, the manuscript is well constructed and analysis is well performed. In abstract, the authors summarized the main research question and key findings. The description of study subject and results are detailed and correct. Data collected are interpreted accurately and the results support the conclusion.
This manuscript reads well. The figures are clear and readable and support the findings. In my opinion, the manuscript is suitable for publication in Energies with minor revision. Two remarks are listed below:
- Figure 2: The lithology legend is missing. Lithological symbols presented in a column should be provided under the stratigraphic column and explained in the figure caption.
- The column shows that the Paleocene formation is unconformably underlain by the Upper Cretaceous rocks. According to patterns used it may be assumed that these represent igneous rocks? and clastic sedimentary deposits. Please provide the legend for the Upper Cretaceous unit as also the appropriate explication in the Geological setting paragraph regarding the basement of the Xihu Sag reservoir.
Author Response
First of all, we thank both the reviewers and editor for their thorough and valuable review, as well as constructive comments and fruitful suggestions, which have contributed in improving the quality of the paper.
Point 1:
Figure 2: The lithology legend is missing. Lithological symbols presented in a column should be provided under the stratigraphic column and explained in the figure caption.
Response 1:
The stratigraphic column of Xihu sag has been updated. And lithological symbols have been provided under the stratigraphic column.
Point 2:
The column shows that the Paleocene formation is unconformably underlain by the Upper Cretaceous rocks. According to patterns used it may be assumed that these represent igneous rocks? and clastic sedimentary deposits. Please provide the legend for the Upper Cretaceous unit as also the appropriate explication in the Geological setting paragraph regarding the basement of the Xihu Sag reservoir.
Response 2:
Xihu sag is a negative structural unit formed in Cenozoic in the East China Sea shelf basin. According to the data of drilling gravity and magnetic exploration, The stratigraphy of Xihu Sag is as follow Pleistocene Donghai Group (Qd), Pliocene Santan Formation (N2s), Miocene Liulang Formation (N1ll), Miocene Yuquan Formation (N1yq), Miocene Longjing Formation (N1lj), Oligocene Huagang Formation (E3h), Eocene Pinghu Formation (E2p), Eocene Baoshi Formation (E2bs), Paleocene (E1). The basement material of Xihu sag is mainly composed of a large number of Cretaceous igneous rocks, including the intrusion granite and contact metamorphic rock.
In order to improve the academic and authority of the studying, we add 2 references about the basement of Xihu sag, including:
[22] Shen W F, Yu Z K, Diao H, et al. Simulation of heat flow evolution history in Xihu sagand its significance for hydrocarbon accumulation[J]. China Offshore Oil Gas, 2020, 32(1): 42-53. DOI: 11935/j.issn.1673-1506.2020.01.005.
[23] Jiang Y M, Zou W, Liu J S, Tang X J, He, X J. Genetic Mechanism of Inversion Anticline Structure at the End of Miocene in Xihu Sag, East China Sea: A New Understanding of Basement Structure Difference[j].Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences45(3):968. DOI: 3799/dqkx.2019.292.
Thank you very much for your support and help.
Sincerely yours,
Ruizhao Yang
Author Response File: Author Response.docx
