Using nanoindentation to quantify the mechanical profile of Wufeng-Longmaxi formation shale in Southwest China: Link to sedimentary conditions

Wang, Jianfeng; Yang, Chao; Liu, Yuke; Jiang, Wenmin; Li, Yun; Zhang, Ting; Zheng, Yijun; Liao, Yuhong; Huo, Qiuli; Fu, Li; Wang, Yusheng; Peng, Ping'an; Xiong, Yongqiang

doi:https://doi.org/10.5194/egusphere-2025-1365

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https://doi.org/10.5194/egusphere-2025-1365

Preprints

08 Apr 2025

| 08 Apr 2025

Using nanoindentation to quantify the mechanical profile of Wufeng-Longmaxi formation shale in Southwest China: Link to sedimentary conditions

Jianfeng Wang, Chao Yang, Yuke Liu, Wenmin Jiang, Yun Li, Ting Zhang, Yijun Zheng, Yuhong Liao, Qiuli Huo, Li Fu, Yusheng Wang, Ping'an Peng, and Yongqiang Xiong

Abstract. The fine construction of a continuous mechanical profile for the Wufeng to Longmaxi (WF-LMX) Formation sequence is crucial for designing hydraulic fracturing projects in shale gas development. However, the microscale mechanical profile of WF-LMX formation shale and its relationship to sedimentary conditions are poorly understood. This study investigates the mechanical profile of the WF-LMX Formation sequence using nanoindentation. A total of 27 cutting samples were collected at one to one-half meter intervals from the Sanquan-1 well. Nanoindentation testing, rock mineralogy, major element analysis, and porosimetry were performed. The results showed that the WF-LMX shales in this study region were deposited in a passive continental margin environment, primarily from biogenic silica, in a warm and humid climate in a predominantly freshwater environment. Mechanical properties (hardness, fracture toughness, Young's modulus, and brittle index) varied synchronously with mineral and organic content across the vertical drilling profile, reflecting changes in lithology and sedimentary facies within the WF-LMX Formations. Shales in the upper part of the WF Formation and lower part of the LMX Formation, belonging to the deep-water shelf facies, exhibited high mechanical properties. Quartz and clay play a dominant role in controlling shale mechanics, while the minor rock constituents, nanoporosity have little effect. In particular, biogenic silica (authigenic quartz) plays an important role in increasing the brittleness of shale. The effect of shale constituents on micromechanics is essentially controlled by the sedimentary environment. Additionally, the potential of using nanoindentation to effectively assess shale brittleness was also demonstrated. This study provides a continuous and accurate interpretation profile of mechanical parameters and is helpful in determining favorable intervals for hydraulic fracturing in the design of shale gas development.

Received: 22 Mar 2025 – Discussion started: 08 Apr 2025

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this paper. While Copernicus Publications makes every effort to include appropriate place names, the final responsibility lies with the authors. Views expressed in the text are those of the authors and do not necessarily reflect the views of the publisher.

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Journal article(s) based on this preprint

10 Sep 2025

Using nanoindentation to quantify the mechanical profile of the Wufeng–Longmaxi Formation in southwestern China: link to sedimentary conditions

Jianfeng Wang, Chao Yang, Yuke Liu, Wenmin Jiang, Yun Li, Ting Zhang, Yijun Zheng, Yuhong Liao, Qiuli Huo, Li Fu, Yusheng Wang, Ping'an Peng, and Yongqiang Xiong

Solid Earth, 16, 819–839, https://doi.org/10.5194/se-16-819-2025,https://doi.org/10.5194/se-16-819-2025, 2025

Short summary

Jianfeng Wang, Chao Yang, Yuke Liu, Wenmin Jiang, Yun Li, Ting Zhang, Yijun Zheng, Yuhong Liao, Qiuli Huo, Li Fu, Yusheng Wang, Ping'an Peng, and Yongqiang Xiong

Interactive discussion

Status: closed

RC1:
'Comment on egusphere-2025-1365', Anonymous Referee #1, 07 May 2025

The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2025/egusphere-2025-1365/egusphere-2025-1365-RC1-supplement.pdf

Citation: https://doi.org/10.5194/egusphere-2025-1365-RC1
- AC2:
  'Reply on RC1', Jianfeng Wang, 03 Jun 2025
  Reviewer #1: This manuscript is quite substantial in content and provides relevant analysis from a novel perspective. It focuses on the microscale mechanical properties of the marine shale of the WF-LMX Formation and how these mechanical properties are related to sedimentary conditions. Overall, the manuscript is well organized, the expression of the results is clear enough, and the key points are highlighted. I propose to accept it with some modifications.
  Line 251. Why do you use 7×7 grid indentations? What is your basis for that or do you have any references?
  
  Response: We used 7×7 grid indentations based on our previous study (Wang et al., 2022). This study demonstrated a representative elementary area (REA) of shale at the microscale, being of no less than 300 μm*300 μm. The resulting areas under the 7×7 grid indentations of this study is approximately 450 μm × 450 μm, which is much larger than the REA of shale proposed by Liu et al. (2018). This ensures an unbiased statistical characterization. We have added the reference to the revised manuscript. Line 252.
  Line 250-258. Does your shale exhibit a laminated texture? If the shale is of the laminar type, the method used to determine its bulk mechanical properties may not be appropriate. This is because some laminae within it can be several centimeters thick.
  
  Response: Thank you for your insightful comment. You are correct. If the shale is laminar and the laminae are relatively thick, then the method used to determine its bulk mechanical properties may be incorrect. However, we did not find any obvious laminar structure in our shales. Unlike continental shale, our marine shale comes in the form of blocks, so a laminated texture is uncommon. We have included an explanation of this in the revised manuscript (Lines 255-256).
  The indents in Fig.3 are not clear. Please mark them on the figure.
  
  Response: We have marked the indent with yellow circles in the Fig. 3. Please find it in the revised manuscript.
  Figure 4. EDS only gives elemental distributions. How exactly was mineralogy determined, knowing that many minerals can have identical Si/O distributions?
  
  Response: EDS can determine elemental distributions. However, we can identify the mineral composition of shale using these distributions. As we know, the shale matrix includes quartz, feldspar, carbonate, pyrite, and so on. As Fig. 4f shows, the quartz particle contains only Si and O elements. The particle is large and has a smooth surface. If the particle contains other elements, then it may be a different mineral. Therefore, based on the elemental distribution and morphology, we can conclude that the particle is quartz.
  Figure 5 displays the load-displacement curves on fracture areas. Do you use these data for statistical mechanical analysis? If not, please provide an explanation.
  
  Response: For the indents in areas with cracks, the ultimate load that can be loaded generally cannot reach the set peak load, and the pop-in phenomenon is usually present in the load-displacement curve. Therefore, data obtained from these curves are not used for statistical analysis. We have included an explanation of this phenomenon in the revised manuscript (Lines 341-342).
  Line 406-410. Since this is the results section, do not include any analysis or discussion; just present the obtained results directly.
  
  Response: We have removed these sentences.
  Table 2 is not of much significance in the main text and can therefore be placed in the Supplementary Files.
  
  Response: We have moved this table to the Supplementary File (Table S4).
  Line 517, Please provide references. Actually, it would be better to include data on trace elements in section 5.1.4. Please provide more literature to support the explanations in this part.
  
  Response:
  (1) Thank you for your suggestion. We have added the reference (Line 515-516).
  (2) Thank you for your insightful suggestion. It is better to include trace elements in order to more comprehensively reveal the sedimentary paleoenvironment of shale. Unfortunately, we haven't conducted experiments on this topic. Given this limitation, we have removed the discussion of ancient paleosalinity of seawater during shale deposition from the text because it requires data on trace elements. For the redox conditions of seawater, we have added more references to support the explanations (Wang et al., 2024; Wei et al., 2021) (Line 516).
  Line 574. It is well known that the fracture toughness of shale increases with increasing clay content. However, in your study, fracture toughness is positively related to hardness and Young's modulus. Can you explain why?
  
  Response: Thank you for this question. In fact, the microfracture toughness measured by nanoindentation is negatively correlated with clay mineral content. This has also been reported in previous articles (Gupta et al., 2020). The previous positive correlation between Young's modulus and fracture toughness indirectly confirmed this conclusion as well (Gupta et al., 2020; Liu et al., 2016; Wang et al., 2022). We believe the difference between macro- and microfracture toughness may be related to sample volume. During nanoindentation test, the indenter primarily affects local mineral particles, such as clay minerals or quartz. Clay minerals usually have low hardness and are prone to plastic deformation. Areas rich in clay are prone to microcrack propagation, which results in a reduction in local fracture toughness. At the macro scale, shale is a heterogeneous composite material. Clay minerals may inhibit macrocrack propagation through energy dissipation mechanisms such as plastic deformation and particle slip. The ductility of materials reinforced with high clay content requires more energy to fracture, showing that macro toughness is improved.
  Lines 635-638. Traditional uniaxial/triaxial compression tests can also predict mechanical parameters for both the X1 and X3 planes. However, it is important to emphasize the advantages offered by nanoindentation techniques.
  
  Response: Thanks for your valuable comment. We have modified it. That is “Compared with Young's modulus from conventional logging, we can not only obtain the Young's modulus of shale via drill cuttings, but also predict its brittleness in the X1 and X3 planes (Figure 7).” Lines 636-638.
  References
  Gupta, I., Sondergeld, C., and Rai, C.: Fracture toughness in shales using nano-indentation. Journal of Petroleum Science and Engineering, 191, 107222. doi:10.1016/j.petrol.2020.107222, 2020.
  Liu, K., Ostadhassan, M., and Bubach, B.: Applications of nano-indentation methods to estimate nanoscale mechanical properties of shale reservoir rocks. J. Nat. Gas Sci. Eng., 35, 1310-1319. doi:10.1016/j.jngse.2016.09.068, 2016.
  Liu, K., Ostadhassan, M., Bubach, B., Ling, K., Tokhmechi, B., and Robert, D.: Statistical grid nanoindentation analysis to estimate macro-mechanical properties of the Bakken Shale. J. Nat. Gas Sci. Eng., 53, 181-190. doi:10.1016/j.jngse.2018.03.005, 2018.
  Wang, J., Yang, C., Liu, Y., and Xiong, Y.: Nanoindentation investigation of mechanical and creep properties of continental Triassic Yanchang Formation shale, Ordos Basin. Interpretation, 10, SJ29-SJ41. 2022.
  Wang, Q., Feng, Y., Gao, P., Meng, G., Lu, C., Fan, Q., Li, G., Tan, Y., and Xiao, X.: Influence of the sedimentary environment of the Wufeng-Longmaxi shale on organic matter accumulation in the Dingshan area, Sichuan Basin. Front. Earth Sci., 12, 1457377. doi:10.3389/feart.2024.1457377, 2024.
  Wei, C., Dong, T., He, Z., He, S., He, Q., Yang, R., Guo, X., and Hou, Y.: Major, trace-elemental and sedimentological characterization of the upper Ordovician Wufeng-lower Silurian Longmaxi formations, Sichuan Basin, south China: Insights into the effect of relative sea-level fluctuations on organic matter accumulation in shales. Mar. Pet. Geol., 126, 104905. doi:10.1016/j.marpetgeo.2021.104905, 2021.
  
  Citation: https://doi.org/10.5194/egusphere-2025-1365-AC2
RC2:
'Comment on egusphere-2025-1365', Bin Xiao, 20 May 2025
The paper analyzed the mineral composition, sedimentary environment, and micro mechanical characteristics of the shale in the Wufeng and Longmaxi formations. Proving the potential of using nanoindentation to effectively evaluate shale brittleness. Provided a continuous and accurate mechanical parameter interpretation profile, which helps determine favorable intervals for hydraulic fracturing in shale gas development design. In principle, I think the manuscript with minor revision could be suitable for the publication in this journal. The following major concerns may be useful for the manuscript improvement.
For "WF-LMX formation", "WF-LMX Formation" and "WF-LMX Formations" in the abstract, it is recommended to express them uniformly and correctly.

The map of China shown in Figure 1 is incomplete. It is suggested to be modified.

When using the Chemical Alteration Index (CIA) in the text, have the potassium mineralization of shale and the recycling of ancient shale been considered?
Citation: https://doi.org/10.5194/egusphere-2025-1365-RC2
- AC1: 'Reply on RC2', Jianfeng Wang, 03 Jun 2025
  
  （1）For "WF-LMX formation", "WF-LMX Formation" and "WF-LMX Formations" in the abstract, it is recommended to express them uniformly and correctly.
  Response: Thank you for this comment. We have unified them into the WF-LMX Formation, and we have also checked the full manuscript for consistency.
  （2）The map of China shown in Figure 1 is incomplete. It is suggested to be modified.
  Response: Thank you for this comment. We have modified Figure 1. Please check the revised version in the manuscript.
  （3）When using the Chemical Alteration Index (CIA) in the text, have the potassium mineralization of shale and the recycling of ancient shale been considered?
  Response: We apologize for not clearly explaining the conditions for applying the Chemical Alteration Index (CIA).
  1) Regarding the potassium mineralization of shale, the weathering line of the sample is generally parallel to the A-CN boundary (Figure 9), indicating that potassium has not been significantly leached during weathering and may have been only weakly affected by potassium metasomatism. Additionally, we cross-validated the weathering conditions using the Plagioclase Index of Alteration (PIA).
  2) For the recycling of ancient shale, We have added the explanation. Cox et al. (1995) proposed the Index of Component Variation (ICV), which is calculated as the molar ratio of (Fe₂O₃+ K₂O + Na₂O + CaO* + MgO +MnO+TiO2) to Al₂O₃. According to Cullers and Podkovyrov (2000), an ICV greater than 1 in fine-grained clastic rocks suggests low clay content and originally deposition in a tectonically active area. Conversely, an ICV less than 1 indicates high clay content resulting from chemical weathering or redeposition. In this study, the ICV values of the samples (1.18-1.46, see Table S2) exceed 1, which confirms the first deposition without redeposition and can reflect the weathering degree and paleoclimate of the source area. We added the influence of these two conditions in the revised manuscript (Lines 470-476 and 487-489).
  
  Citation: https://doi.org/10.5194/egusphere-2025-1365-AC1

Interactive discussion

Status: closed

RC1:
'Comment on egusphere-2025-1365', Anonymous Referee #1, 07 May 2025

The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2025/egusphere-2025-1365/egusphere-2025-1365-RC1-supplement.pdf

Citation: https://doi.org/10.5194/egusphere-2025-1365-RC1
- AC2:
  'Reply on RC1', Jianfeng Wang, 03 Jun 2025
  Reviewer #1: This manuscript is quite substantial in content and provides relevant analysis from a novel perspective. It focuses on the microscale mechanical properties of the marine shale of the WF-LMX Formation and how these mechanical properties are related to sedimentary conditions. Overall, the manuscript is well organized, the expression of the results is clear enough, and the key points are highlighted. I propose to accept it with some modifications.
  Line 251. Why do you use 7×7 grid indentations? What is your basis for that or do you have any references?
  
  Response: We used 7×7 grid indentations based on our previous study (Wang et al., 2022). This study demonstrated a representative elementary area (REA) of shale at the microscale, being of no less than 300 μm*300 μm. The resulting areas under the 7×7 grid indentations of this study is approximately 450 μm × 450 μm, which is much larger than the REA of shale proposed by Liu et al. (2018). This ensures an unbiased statistical characterization. We have added the reference to the revised manuscript. Line 252.
  Line 250-258. Does your shale exhibit a laminated texture? If the shale is of the laminar type, the method used to determine its bulk mechanical properties may not be appropriate. This is because some laminae within it can be several centimeters thick.
  
  Response: Thank you for your insightful comment. You are correct. If the shale is laminar and the laminae are relatively thick, then the method used to determine its bulk mechanical properties may be incorrect. However, we did not find any obvious laminar structure in our shales. Unlike continental shale, our marine shale comes in the form of blocks, so a laminated texture is uncommon. We have included an explanation of this in the revised manuscript (Lines 255-256).
  The indents in Fig.3 are not clear. Please mark them on the figure.
  
  Response: We have marked the indent with yellow circles in the Fig. 3. Please find it in the revised manuscript.
  Figure 4. EDS only gives elemental distributions. How exactly was mineralogy determined, knowing that many minerals can have identical Si/O distributions?
  
  Response: EDS can determine elemental distributions. However, we can identify the mineral composition of shale using these distributions. As we know, the shale matrix includes quartz, feldspar, carbonate, pyrite, and so on. As Fig. 4f shows, the quartz particle contains only Si and O elements. The particle is large and has a smooth surface. If the particle contains other elements, then it may be a different mineral. Therefore, based on the elemental distribution and morphology, we can conclude that the particle is quartz.
  Figure 5 displays the load-displacement curves on fracture areas. Do you use these data for statistical mechanical analysis? If not, please provide an explanation.
  
  Response: For the indents in areas with cracks, the ultimate load that can be loaded generally cannot reach the set peak load, and the pop-in phenomenon is usually present in the load-displacement curve. Therefore, data obtained from these curves are not used for statistical analysis. We have included an explanation of this phenomenon in the revised manuscript (Lines 341-342).
  Line 406-410. Since this is the results section, do not include any analysis or discussion; just present the obtained results directly.
  
  Response: We have removed these sentences.
  Table 2 is not of much significance in the main text and can therefore be placed in the Supplementary Files.
  
  Response: We have moved this table to the Supplementary File (Table S4).
  Line 517, Please provide references. Actually, it would be better to include data on trace elements in section 5.1.4. Please provide more literature to support the explanations in this part.
  
  Response:
  (1) Thank you for your suggestion. We have added the reference (Line 515-516).
  (2) Thank you for your insightful suggestion. It is better to include trace elements in order to more comprehensively reveal the sedimentary paleoenvironment of shale. Unfortunately, we haven't conducted experiments on this topic. Given this limitation, we have removed the discussion of ancient paleosalinity of seawater during shale deposition from the text because it requires data on trace elements. For the redox conditions of seawater, we have added more references to support the explanations (Wang et al., 2024; Wei et al., 2021) (Line 516).
  Line 574. It is well known that the fracture toughness of shale increases with increasing clay content. However, in your study, fracture toughness is positively related to hardness and Young's modulus. Can you explain why?
  
  Response: Thank you for this question. In fact, the microfracture toughness measured by nanoindentation is negatively correlated with clay mineral content. This has also been reported in previous articles (Gupta et al., 2020). The previous positive correlation between Young's modulus and fracture toughness indirectly confirmed this conclusion as well (Gupta et al., 2020; Liu et al., 2016; Wang et al., 2022). We believe the difference between macro- and microfracture toughness may be related to sample volume. During nanoindentation test, the indenter primarily affects local mineral particles, such as clay minerals or quartz. Clay minerals usually have low hardness and are prone to plastic deformation. Areas rich in clay are prone to microcrack propagation, which results in a reduction in local fracture toughness. At the macro scale, shale is a heterogeneous composite material. Clay minerals may inhibit macrocrack propagation through energy dissipation mechanisms such as plastic deformation and particle slip. The ductility of materials reinforced with high clay content requires more energy to fracture, showing that macro toughness is improved.
  Lines 635-638. Traditional uniaxial/triaxial compression tests can also predict mechanical parameters for both the X1 and X3 planes. However, it is important to emphasize the advantages offered by nanoindentation techniques.
  
  Response: Thanks for your valuable comment. We have modified it. That is “Compared with Young's modulus from conventional logging, we can not only obtain the Young's modulus of shale via drill cuttings, but also predict its brittleness in the X1 and X3 planes (Figure 7).” Lines 636-638.
  References
  Gupta, I., Sondergeld, C., and Rai, C.: Fracture toughness in shales using nano-indentation. Journal of Petroleum Science and Engineering, 191, 107222. doi:10.1016/j.petrol.2020.107222, 2020.
  Liu, K., Ostadhassan, M., and Bubach, B.: Applications of nano-indentation methods to estimate nanoscale mechanical properties of shale reservoir rocks. J. Nat. Gas Sci. Eng., 35, 1310-1319. doi:10.1016/j.jngse.2016.09.068, 2016.
  Liu, K., Ostadhassan, M., Bubach, B., Ling, K., Tokhmechi, B., and Robert, D.: Statistical grid nanoindentation analysis to estimate macro-mechanical properties of the Bakken Shale. J. Nat. Gas Sci. Eng., 53, 181-190. doi:10.1016/j.jngse.2018.03.005, 2018.
  Wang, J., Yang, C., Liu, Y., and Xiong, Y.: Nanoindentation investigation of mechanical and creep properties of continental Triassic Yanchang Formation shale, Ordos Basin. Interpretation, 10, SJ29-SJ41. 2022.
  Wang, Q., Feng, Y., Gao, P., Meng, G., Lu, C., Fan, Q., Li, G., Tan, Y., and Xiao, X.: Influence of the sedimentary environment of the Wufeng-Longmaxi shale on organic matter accumulation in the Dingshan area, Sichuan Basin. Front. Earth Sci., 12, 1457377. doi:10.3389/feart.2024.1457377, 2024.
  Wei, C., Dong, T., He, Z., He, S., He, Q., Yang, R., Guo, X., and Hou, Y.: Major, trace-elemental and sedimentological characterization of the upper Ordovician Wufeng-lower Silurian Longmaxi formations, Sichuan Basin, south China: Insights into the effect of relative sea-level fluctuations on organic matter accumulation in shales. Mar. Pet. Geol., 126, 104905. doi:10.1016/j.marpetgeo.2021.104905, 2021.
  
  Citation: https://doi.org/10.5194/egusphere-2025-1365-AC2
RC2:
'Comment on egusphere-2025-1365', Bin Xiao, 20 May 2025
The paper analyzed the mineral composition, sedimentary environment, and micro mechanical characteristics of the shale in the Wufeng and Longmaxi formations. Proving the potential of using nanoindentation to effectively evaluate shale brittleness. Provided a continuous and accurate mechanical parameter interpretation profile, which helps determine favorable intervals for hydraulic fracturing in shale gas development design. In principle, I think the manuscript with minor revision could be suitable for the publication in this journal. The following major concerns may be useful for the manuscript improvement.
For "WF-LMX formation", "WF-LMX Formation" and "WF-LMX Formations" in the abstract, it is recommended to express them uniformly and correctly.

The map of China shown in Figure 1 is incomplete. It is suggested to be modified.

When using the Chemical Alteration Index (CIA) in the text, have the potassium mineralization of shale and the recycling of ancient shale been considered?
Citation: https://doi.org/10.5194/egusphere-2025-1365-RC2
- AC1: 'Reply on RC2', Jianfeng Wang, 03 Jun 2025
  
  （1）For "WF-LMX formation", "WF-LMX Formation" and "WF-LMX Formations" in the abstract, it is recommended to express them uniformly and correctly.
  Response: Thank you for this comment. We have unified them into the WF-LMX Formation, and we have also checked the full manuscript for consistency.
  （2）The map of China shown in Figure 1 is incomplete. It is suggested to be modified.
  Response: Thank you for this comment. We have modified Figure 1. Please check the revised version in the manuscript.
  （3）When using the Chemical Alteration Index (CIA) in the text, have the potassium mineralization of shale and the recycling of ancient shale been considered?
  Response: We apologize for not clearly explaining the conditions for applying the Chemical Alteration Index (CIA).
  1) Regarding the potassium mineralization of shale, the weathering line of the sample is generally parallel to the A-CN boundary (Figure 9), indicating that potassium has not been significantly leached during weathering and may have been only weakly affected by potassium metasomatism. Additionally, we cross-validated the weathering conditions using the Plagioclase Index of Alteration (PIA).
  2) For the recycling of ancient shale, We have added the explanation. Cox et al. (1995) proposed the Index of Component Variation (ICV), which is calculated as the molar ratio of (Fe₂O₃+ K₂O + Na₂O + CaO* + MgO +MnO+TiO2) to Al₂O₃. According to Cullers and Podkovyrov (2000), an ICV greater than 1 in fine-grained clastic rocks suggests low clay content and originally deposition in a tectonically active area. Conversely, an ICV less than 1 indicates high clay content resulting from chemical weathering or redeposition. In this study, the ICV values of the samples (1.18-1.46, see Table S2) exceed 1, which confirms the first deposition without redeposition and can reflect the weathering degree and paleoclimate of the source area. We added the influence of these two conditions in the revised manuscript (Lines 470-476 and 487-489).
  
  Citation: https://doi.org/10.5194/egusphere-2025-1365-AC1

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

AR by Jianfeng Wang on behalf of the Authors (03 Jun 2025) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (06 Jun 2025) by Jessica McBeck

RR by Anonymous Referee #1 (16 Jun 2025)

RR by Bin Xiao (16 Jun 2025)

ED: Publish as is (17 Jun 2025) by Jessica McBeck

ED: Publish as is (22 Jun 2025) by Florian Fusseis (Executive editor)

AR by Jianfeng Wang on behalf of the Authors (28 Jun 2025) Manuscript

Journal article(s) based on this preprint

10 Sep 2025

Using nanoindentation to quantify the mechanical profile of the Wufeng–Longmaxi Formation in southwestern China: link to sedimentary conditions

Jianfeng Wang, Chao Yang, Yuke Liu, Wenmin Jiang, Yun Li, Ting Zhang, Yijun Zheng, Yuhong Liao, Qiuli Huo, Li Fu, Yusheng Wang, Ping'an Peng, and Yongqiang Xiong

Solid Earth, 16, 819–839, https://doi.org/10.5194/se-16-819-2025,https://doi.org/10.5194/se-16-819-2025, 2025

Short summary

Jianfeng Wang, Chao Yang, Yuke Liu, Wenmin Jiang, Yun Li, Ting Zhang, Yijun Zheng, Yuhong Liao, Qiuli Huo, Li Fu, Yusheng Wang, Ping'an Peng, and Yongqiang Xiong

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https://doi.org/10.5194/egusphere-2025-1365-supplement

Jianfeng Wang, Chao Yang, Yuke Liu, Wenmin Jiang, Yun Li, Ting Zhang, Yijun Zheng, Yuhong Liao, Qiuli Huo, Li Fu, Yusheng Wang, Ping'an Peng, and Yongqiang Xiong

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The Wufeng to Longmaxi (WF-LMX) Formations are the most important shale gas play in China. Here, we present a feasible approach using nanoindentation to characterize the mechanical properties of the WF-LMX Formations. Mechanical properties varied synchronously with mineral and organic content across the vertical drilling profile, reflecting changes in lithology and sedimentary facies. The effect of shale constituents on micromechanics is essentially controlled by the sedimentary environment.


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