Effects of Deep Fluids on Middle Permian Dolomite of the Western Sichuan Basin
Deep fluid activity is closely related to carbonate reservoir transformation as well as oil and gas accumulation. The large-scale deep fluid activity caused by Emeishan large igneous province (ELIP) brought a lot of deep material and energy to Sichuan Basin and changed the paleogeothermal and geoche...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-06-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2022.910453/full |
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| author | Huiwen Huang Huiwen Huang Hongde Chen Hongde Chen Fei Huo Fei Huo Shuai Yang Shuai Yang Anqing Chen Anqing Chen |
| author_facet | Huiwen Huang Huiwen Huang Hongde Chen Hongde Chen Fei Huo Fei Huo Shuai Yang Shuai Yang Anqing Chen Anqing Chen |
| author_sort | Huiwen Huang |
| collection | DOAJ |
| description | Deep fluid activity is closely related to carbonate reservoir transformation as well as oil and gas accumulation. The large-scale deep fluid activity caused by Emeishan large igneous province (ELIP) brought a lot of deep material and energy to Sichuan Basin and changed the paleogeothermal and geochemical field of the region they flowed through, which had an important impact on the formation of the Middle Permian dolomite reservoir in Western Sichuan. Through comprehensive analyses of petrographic, geochemical, and fluid inclusion data from two drill cores and three outcrop sections of the Middle Permian Formation in the Western Sichuan Basin, the dolomitizing fluid, dolomite genesis, and effect of deep fluid were discussed. The dolomite was divided into four types which are matrix dolomites (Md1, Md2, and Md3) and cement dolomites (Cd). Among them, the Md1 was formed in penecontemporaneous seawater by seepage reflux dolomitization, while Md2 was formed in heated Permian seawater through thermal convection. In the northwest of the study area, the Md3 and Cd were formed by higher-temperature thermal convection without hydrothermal. In the southwest of the study area, the lower δ13C value and Sr contents, higher Mn contents and 87Sr/86Sr ratios, and positive Eu anomalies as well as much higher Th and salinity values of inclusions show that hydrothermal participated in the dolomitization, forming the Md3 and Cd through structure-hydrothermal dolomitization and the thermal convection of seawater mixed with hydrothermal. The deep fluid activities of ELIP provided both the material source (Mg2+) for the dolomitization process and the migration motive power for the dolomitization fluid. From the southwest to northwest, with the deep fluid activity decreasing, the abundance of Md3 and Cd, which are closely related to the hydrothermal solution, reduced. |
| first_indexed | 2024-12-11T21:48:23Z |
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| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-11T21:48:23Z |
| publishDate | 2022-06-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-f3d75e8adf5142348ecb737b55c11ef22022-12-22T00:49:32ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632022-06-011010.3389/feart.2022.910453910453Effects of Deep Fluids on Middle Permian Dolomite of the Western Sichuan BasinHuiwen Huang0Huiwen Huang1Hongde Chen2Hongde Chen3Fei Huo4Fei Huo5Shuai Yang6Shuai Yang7Anqing Chen8Anqing Chen9Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, ChinaState Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, ChinaInstitute of Sedimentary Geology, Chengdu University of Technology, Chengdu, ChinaState Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, ChinaInstitute of Sedimentary Geology, Chengdu University of Technology, Chengdu, ChinaState Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, ChinaInstitute of Sedimentary Geology, Chengdu University of Technology, Chengdu, ChinaState Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, ChinaInstitute of Sedimentary Geology, Chengdu University of Technology, Chengdu, ChinaState Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, ChinaDeep fluid activity is closely related to carbonate reservoir transformation as well as oil and gas accumulation. The large-scale deep fluid activity caused by Emeishan large igneous province (ELIP) brought a lot of deep material and energy to Sichuan Basin and changed the paleogeothermal and geochemical field of the region they flowed through, which had an important impact on the formation of the Middle Permian dolomite reservoir in Western Sichuan. Through comprehensive analyses of petrographic, geochemical, and fluid inclusion data from two drill cores and three outcrop sections of the Middle Permian Formation in the Western Sichuan Basin, the dolomitizing fluid, dolomite genesis, and effect of deep fluid were discussed. The dolomite was divided into four types which are matrix dolomites (Md1, Md2, and Md3) and cement dolomites (Cd). Among them, the Md1 was formed in penecontemporaneous seawater by seepage reflux dolomitization, while Md2 was formed in heated Permian seawater through thermal convection. In the northwest of the study area, the Md3 and Cd were formed by higher-temperature thermal convection without hydrothermal. In the southwest of the study area, the lower δ13C value and Sr contents, higher Mn contents and 87Sr/86Sr ratios, and positive Eu anomalies as well as much higher Th and salinity values of inclusions show that hydrothermal participated in the dolomitization, forming the Md3 and Cd through structure-hydrothermal dolomitization and the thermal convection of seawater mixed with hydrothermal. The deep fluid activities of ELIP provided both the material source (Mg2+) for the dolomitization process and the migration motive power for the dolomitization fluid. From the southwest to northwest, with the deep fluid activity decreasing, the abundance of Md3 and Cd, which are closely related to the hydrothermal solution, reduced.https://www.frontiersin.org/articles/10.3389/feart.2022.910453/fulldeep fluidshydrocarbon accumulationsdolomite reservoirsSichuan Basindolomitization |
| spellingShingle | Huiwen Huang Huiwen Huang Hongde Chen Hongde Chen Fei Huo Fei Huo Shuai Yang Shuai Yang Anqing Chen Anqing Chen Effects of Deep Fluids on Middle Permian Dolomite of the Western Sichuan Basin Frontiers in Earth Science deep fluids hydrocarbon accumulations dolomite reservoirs Sichuan Basin dolomitization |
| title | Effects of Deep Fluids on Middle Permian Dolomite of the Western Sichuan Basin |
| title_full | Effects of Deep Fluids on Middle Permian Dolomite of the Western Sichuan Basin |
| title_fullStr | Effects of Deep Fluids on Middle Permian Dolomite of the Western Sichuan Basin |
| title_full_unstemmed | Effects of Deep Fluids on Middle Permian Dolomite of the Western Sichuan Basin |
| title_short | Effects of Deep Fluids on Middle Permian Dolomite of the Western Sichuan Basin |
| title_sort | effects of deep fluids on middle permian dolomite of the western sichuan basin |
| topic | deep fluids hydrocarbon accumulations dolomite reservoirs Sichuan Basin dolomitization |
| url | https://www.frontiersin.org/articles/10.3389/feart.2022.910453/full |
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