The origin and depositional processes of shell layers in the Jurassic Ziliujing Formation in the Sichuan Basin and their influences on petroleum accumulation
Unlike other lacustrine shale formations in which carbonate and siliceous interlayers are intercalated, the Dongyuemiao shale is different due to its abundant shell laminae and interlayers. Due to the lack of studies on shell laminae and interlayers, their influence on oil accumulation is still uncl...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-07-01
|
| Series: | Frontiers in Earth Science |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2025.1590482/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850100174384267264 |
|---|---|
| author | Hanyong Bao Yi Shu Qiming Wang Youheng Zheng Miankun Chen Yongchao Lu Haotian Liu Wei Peng |
| author_facet | Hanyong Bao Yi Shu Qiming Wang Youheng Zheng Miankun Chen Yongchao Lu Haotian Liu Wei Peng |
| author_sort | Hanyong Bao |
| collection | DOAJ |
| description | Unlike other lacustrine shale formations in which carbonate and siliceous interlayers are intercalated, the Dongyuemiao shale is different due to its abundant shell laminae and interlayers. Due to the lack of studies on shell laminae and interlayers, their influence on oil accumulation is still unclear. This study integrated total organic carbonand X-ray diffractiondata, core and thin section observations, field-emission scanning electron microscopy, major and trace element data, and helium porosimetry to investigate the depositional environment and porosity structure of shell interlayers in the shale in the first member of the Dongyuemiao shale (Dong-1 member) and their impact on petroleum accumulation. Results show that Dong-1 member was deposited in a sub-lacustrine fan, and shells and shell fragments were transported by gravity flow. Shells and shell fragments were transported and broken up to under different hydrodynamic conditions, and formed laminae, interlayers, and thick interlayers of shell fragments. In the shell laminae (≤1 cm) and thin interlayers (1-10 cm), micro-scale dissolution pores and microfractures formed in the shell clasts can effectively connect the dissolution pores and black shale matrix. The thick shell interlayers (≥10 cm) lack porosity networks and prevent petroleum migration. The shell laminae and thin interlayers are the storage space and pathway for petroleum storage and migration, while the thick shell layers are seals that prevent petroleum leakage. This integrated study of a shell-rich shale can provide a reference for petroleum exploration and quantitative evaluation of the resources. |
| format | Article |
| id | doaj-art-10fd63f7ac9341c4a194790e60c0cd64 |
| institution | DOAJ |
| issn | 2296-6463 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj-art-10fd63f7ac9341c4a194790e60c0cd642025-08-20T02:40:21ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632025-07-011310.3389/feart.2025.15904821590482The origin and depositional processes of shell layers in the Jurassic Ziliujing Formation in the Sichuan Basin and their influences on petroleum accumulationHanyong Bao0Yi Shu1Qiming Wang2Youheng Zheng3Miankun Chen4Yongchao Lu5Haotian Liu6Wei Peng7Research Institute of Exploration and Development, Jianghan Oilfield Branch Company, Sinopec, Wuhan, ChinaResearch Institute of Exploration and Development, Jianghan Oilfield Branch Company, Sinopec, Wuhan, ChinaSchool of Geosciences, China University of Petroleum (East China), Qingdao, ChinaResearch Institute of Exploration and Development, Jianghan Oilfield Branch Company, Sinopec, Wuhan, ChinaResearch Institute of Exploration and Development, Jianghan Oilfield Branch Company, Sinopec, Wuhan, ChinaKey Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan, ChinaResearch Institute of Exploration and Development, Jianghan Oilfield Branch Company, Sinopec, Wuhan, ChinaResearch Institute of Exploration and Development, Jianghan Oilfield Branch Company, Sinopec, Wuhan, ChinaUnlike other lacustrine shale formations in which carbonate and siliceous interlayers are intercalated, the Dongyuemiao shale is different due to its abundant shell laminae and interlayers. Due to the lack of studies on shell laminae and interlayers, their influence on oil accumulation is still unclear. This study integrated total organic carbonand X-ray diffractiondata, core and thin section observations, field-emission scanning electron microscopy, major and trace element data, and helium porosimetry to investigate the depositional environment and porosity structure of shell interlayers in the shale in the first member of the Dongyuemiao shale (Dong-1 member) and their impact on petroleum accumulation. Results show that Dong-1 member was deposited in a sub-lacustrine fan, and shells and shell fragments were transported by gravity flow. Shells and shell fragments were transported and broken up to under different hydrodynamic conditions, and formed laminae, interlayers, and thick interlayers of shell fragments. In the shell laminae (≤1 cm) and thin interlayers (1-10 cm), micro-scale dissolution pores and microfractures formed in the shell clasts can effectively connect the dissolution pores and black shale matrix. The thick shell interlayers (≥10 cm) lack porosity networks and prevent petroleum migration. The shell laminae and thin interlayers are the storage space and pathway for petroleum storage and migration, while the thick shell layers are seals that prevent petroleum leakage. This integrated study of a shell-rich shale can provide a reference for petroleum exploration and quantitative evaluation of the resources.https://www.frontiersin.org/articles/10.3389/feart.2025.1590482/fullshell laminae and interlayersedimentary environmentpore structurepetroleum accumulationDongyuemiao shale |
| spellingShingle | Hanyong Bao Yi Shu Qiming Wang Youheng Zheng Miankun Chen Yongchao Lu Haotian Liu Wei Peng The origin and depositional processes of shell layers in the Jurassic Ziliujing Formation in the Sichuan Basin and their influences on petroleum accumulation Frontiers in Earth Science shell laminae and interlayer sedimentary environment pore structure petroleum accumulation Dongyuemiao shale |
| title | The origin and depositional processes of shell layers in the Jurassic Ziliujing Formation in the Sichuan Basin and their influences on petroleum accumulation |
| title_full | The origin and depositional processes of shell layers in the Jurassic Ziliujing Formation in the Sichuan Basin and their influences on petroleum accumulation |
| title_fullStr | The origin and depositional processes of shell layers in the Jurassic Ziliujing Formation in the Sichuan Basin and their influences on petroleum accumulation |
| title_full_unstemmed | The origin and depositional processes of shell layers in the Jurassic Ziliujing Formation in the Sichuan Basin and their influences on petroleum accumulation |
| title_short | The origin and depositional processes of shell layers in the Jurassic Ziliujing Formation in the Sichuan Basin and their influences on petroleum accumulation |
| title_sort | origin and depositional processes of shell layers in the jurassic ziliujing formation in the sichuan basin and their influences on petroleum accumulation |
| topic | shell laminae and interlayer sedimentary environment pore structure petroleum accumulation Dongyuemiao shale |
| url | https://www.frontiersin.org/articles/10.3389/feart.2025.1590482/full |
| work_keys_str_mv | AT hanyongbao theoriginanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT yishu theoriginanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT qimingwang theoriginanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT youhengzheng theoriginanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT miankunchen theoriginanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT yongchaolu theoriginanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT haotianliu theoriginanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT weipeng theoriginanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT hanyongbao originanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT yishu originanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT qimingwang originanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT youhengzheng originanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT miankunchen originanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT yongchaolu originanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT haotianliu originanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation AT weipeng originanddepositionalprocessesofshelllayersinthejurassicziliujingformationinthesichuanbasinandtheirinfluencesonpetroleumaccumulation |