Controls of reservoir quality for submarine fan of F4 Formation in the Z oilfield, Illizi Basin, Algeria
Abstract Subaqueous fan reservoirs have emerged as a pivotal focus in recent deep-water oil and gas exploration. In the Illizi Basin of Algeria, a series of submarine fan reservoirs are developed within the Devonian F4 Formation of the Z oilfield. Understanding the genesis of high-quality reservoirs...
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Nature Portfolio
2025-08-01
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| Online Access: | https://doi.org/10.1038/s41598-025-12570-x |
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| author | Changhai Li Weiqiang Li Hui min Ye Qiang Zhu Xuejun Shan Hongping Wang Shengli Wang Ziyu Zhang Xianjie Zhou Zixin Xue Rongtu Ma |
| author_facet | Changhai Li Weiqiang Li Hui min Ye Qiang Zhu Xuejun Shan Hongping Wang Shengli Wang Ziyu Zhang Xianjie Zhou Zixin Xue Rongtu Ma |
| author_sort | Changhai Li |
| collection | DOAJ |
| description | Abstract Subaqueous fan reservoirs have emerged as a pivotal focus in recent deep-water oil and gas exploration. In the Illizi Basin of Algeria, a series of submarine fan reservoirs are developed within the Devonian F4 Formation of the Z oilfield. Understanding the genesis of high-quality reservoirs (defined as those with porosity exceeding 25% and permeability greater than 1000 mD) is crucial for pinpointing high-productivity wells in deep-water submarine fan settings. By integrating core data, thin-section analysis, grain-size data, logging data, and petrophysical property data, this study systematically classifies the depositional environments in the study area, constructs a sedimentary-logging identification template, maps the spatial distribution of lithofacies associations, identifies diagenetic types and evolution sequences, assesses reservoir quality, uncovers the origin of high-quality reservoirs and formulates a genetic model for high-quality reservoirs. The findings show that the study area encompasses 12 rock lithofacies types and 6 lithofacies associations, with braided river channels and interchannel facies being the predominant facies. Four diagenetic processes—compaction, cementation, dissolution, and fracturing—have been identified. Compaction and cementation tend to decrease porosity and permeability, while dissolution and fracturing enhance these properties. Four diagenetic evolution sequences, namely calcite cementation, dolomite cementation, muddy cementation, and quartz cementation, are recognized. Reservoirs associated with calcite and dolomite cementation sequences generally exhibit superior properties due to more strongly developed dissolution, whereas those related to muddy and quartz cementation sequences are of poor quality. Notably, high-quality reservoirs such as LF2, LF7, and LF9 developed in braided river channel microfacies have undergone calcite cementation. These findings verify the critical interplay between depositional facies and diagenetic processes in determining reservoir quality, providing valuable insights for future exploration and production strategies in similar geological settings. |
| format | Article |
| id | doaj-art-53091ac858d44a1eb001e4f5ccb5686f |
| institution | Kabale University |
| issn | 2045-2322 |
| language | English |
| publishDate | 2025-08-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj-art-53091ac858d44a1eb001e4f5ccb5686f2025-08-20T04:01:51ZengNature PortfolioScientific Reports2045-23222025-08-0115112110.1038/s41598-025-12570-xControls of reservoir quality for submarine fan of F4 Formation in the Z oilfield, Illizi Basin, AlgeriaChanghai Li0Weiqiang Li1Hui min Ye2Qiang Zhu3Xuejun Shan4Hongping Wang5Shengli Wang6Ziyu Zhang7Xianjie Zhou8Zixin Xue9Rongtu Ma10Sinopec International Petroleum Exploration and Development CorporationPetroChina Hangzhou Research Institute of GeologySinopec International Petroleum Exploration and Development CorporationSinopec International Petroleum Exploration and Development CorporationSinopec International Petroleum Exploration and Development CorporationPetroChina Hangzhou Research Institute of GeologySinopec International Petroleum Exploration and Development CorporationDepartment of Chemical Engineering and Analytical Sciences, The University of ManchesterSinopec International Petroleum Exploration and Development CorporationSinopec International Petroleum Exploration and Development CorporationSinopec International Petroleum Exploration and Development CorporationAbstract Subaqueous fan reservoirs have emerged as a pivotal focus in recent deep-water oil and gas exploration. In the Illizi Basin of Algeria, a series of submarine fan reservoirs are developed within the Devonian F4 Formation of the Z oilfield. Understanding the genesis of high-quality reservoirs (defined as those with porosity exceeding 25% and permeability greater than 1000 mD) is crucial for pinpointing high-productivity wells in deep-water submarine fan settings. By integrating core data, thin-section analysis, grain-size data, logging data, and petrophysical property data, this study systematically classifies the depositional environments in the study area, constructs a sedimentary-logging identification template, maps the spatial distribution of lithofacies associations, identifies diagenetic types and evolution sequences, assesses reservoir quality, uncovers the origin of high-quality reservoirs and formulates a genetic model for high-quality reservoirs. The findings show that the study area encompasses 12 rock lithofacies types and 6 lithofacies associations, with braided river channels and interchannel facies being the predominant facies. Four diagenetic processes—compaction, cementation, dissolution, and fracturing—have been identified. Compaction and cementation tend to decrease porosity and permeability, while dissolution and fracturing enhance these properties. Four diagenetic evolution sequences, namely calcite cementation, dolomite cementation, muddy cementation, and quartz cementation, are recognized. Reservoirs associated with calcite and dolomite cementation sequences generally exhibit superior properties due to more strongly developed dissolution, whereas those related to muddy and quartz cementation sequences are of poor quality. Notably, high-quality reservoirs such as LF2, LF7, and LF9 developed in braided river channel microfacies have undergone calcite cementation. These findings verify the critical interplay between depositional facies and diagenetic processes in determining reservoir quality, providing valuable insights for future exploration and production strategies in similar geological settings.https://doi.org/10.1038/s41598-025-12570-xSubmarine fanLithofaciesDiagenesisOrigin of high-quality reservoirsIllizi Basin |
| spellingShingle | Changhai Li Weiqiang Li Hui min Ye Qiang Zhu Xuejun Shan Hongping Wang Shengli Wang Ziyu Zhang Xianjie Zhou Zixin Xue Rongtu Ma Controls of reservoir quality for submarine fan of F4 Formation in the Z oilfield, Illizi Basin, Algeria Scientific Reports Submarine fan Lithofacies Diagenesis Origin of high-quality reservoirs Illizi Basin |
| title | Controls of reservoir quality for submarine fan of F4 Formation in the Z oilfield, Illizi Basin, Algeria |
| title_full | Controls of reservoir quality for submarine fan of F4 Formation in the Z oilfield, Illizi Basin, Algeria |
| title_fullStr | Controls of reservoir quality for submarine fan of F4 Formation in the Z oilfield, Illizi Basin, Algeria |
| title_full_unstemmed | Controls of reservoir quality for submarine fan of F4 Formation in the Z oilfield, Illizi Basin, Algeria |
| title_short | Controls of reservoir quality for submarine fan of F4 Formation in the Z oilfield, Illizi Basin, Algeria |
| title_sort | controls of reservoir quality for submarine fan of f4 formation in the z oilfield illizi basin algeria |
| topic | Submarine fan Lithofacies Diagenesis Origin of high-quality reservoirs Illizi Basin |
| url | https://doi.org/10.1038/s41598-025-12570-x |
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