Controlling effects of cap rocks on the formation of deep geothermal resources
Cap rocks with high thermal insulation are important for deep geothermal systems at a depth of 3000‒6000 m. Based on the deep geothermal geological conditions in the Fujian-Guangdong-Hainan area of South China, this study established an ideal geological model of reservoir-cap rock assemblages and si...
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| Format: | Article |
| Language: | English |
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KeAi Communications Co., Ltd.
2023-10-01
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| Series: | Energy Geoscience |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666759223000549 |
| _version_ | 1797672042660626432 |
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| author | Zongquan Hu Ying Zhang Yan Zeng |
| author_facet | Zongquan Hu Ying Zhang Yan Zeng |
| author_sort | Zongquan Hu |
| collection | DOAJ |
| description | Cap rocks with high thermal insulation are important for deep geothermal systems at a depth of 3000‒6000 m. Based on the deep geothermal geological conditions in the Fujian-Guangdong-Hainan area of South China, this study established an ideal geological model of reservoir-cap rock assemblages and simulated the geothermal field distribution of cap rocks of different thicknesses and thermal conductivity. The simulation results show that the vertical geothermal temperature distribution in an uplifted area of a depression was present as inverted mirror reflections relative to the elevated area of the basement. Specifically, the isotherms above the elevated area are convex in shape, while those below the elevated area are concave. There is a temperature equilibrium line between the convex and concave isotherms. The heat flow moves from the depressed area to the uplifted area below the temperature equilibrium line and migrates in an opposite direction above the line. On this base, this study conducted the inversion of geothermal temperature fields in typical areas with thin, moderately thick, and thick cap rocks. The results indicate that, at the depth of 3000–6000 m, areas with thin cap rocks (igneous rock zone in the coastal area of Fujian) mainly host moderate- to low-temperature hydrothermal resources; areas with moderately thick cap rocks (Yuezhong Depression) have the geothermal temperature ranging between 100 °C and 200 °C and may develop moderate- to high-temperature hydrothermal resources and hot dry rocks (HDRs), with the former superimposing on the latter; and areas with thick cap rocks (onshore Beibuwan Basin) have a geothermal temperature of 120‒220 °C, and contains mainly moderate- to high-temperature hydrothermal resources and HDRs. Therefore, it is recommended that the evaluation, exploitation, and utilization of deep geothermal resources be carried out according to the burial depth of the temperature equilibrium line and the specific demand for geothermal resources. |
| first_indexed | 2024-03-11T21:24:20Z |
| format | Article |
| id | doaj.art-dc9d80c5bfda412da0804edd67fd8636 |
| institution | Directory Open Access Journal |
| issn | 2666-7592 |
| language | English |
| last_indexed | 2024-03-11T21:24:20Z |
| publishDate | 2023-10-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Energy Geoscience |
| spelling | doaj.art-dc9d80c5bfda412da0804edd67fd86362023-09-28T05:26:47ZengKeAi Communications Co., Ltd.Energy Geoscience2666-75922023-10-0144100208Controlling effects of cap rocks on the formation of deep geothermal resourcesZongquan Hu0Ying Zhang1Yan Zeng2Petroleum Exploration and Production Research Institute, SINOPEC, Beijing, 102206, ChinaPetroleum Exploration and Production Research Institute, SINOPEC, Beijing, 102206, ChinaCorresponding author.; Petroleum Exploration and Production Research Institute, SINOPEC, Beijing, 102206, ChinaCap rocks with high thermal insulation are important for deep geothermal systems at a depth of 3000‒6000 m. Based on the deep geothermal geological conditions in the Fujian-Guangdong-Hainan area of South China, this study established an ideal geological model of reservoir-cap rock assemblages and simulated the geothermal field distribution of cap rocks of different thicknesses and thermal conductivity. The simulation results show that the vertical geothermal temperature distribution in an uplifted area of a depression was present as inverted mirror reflections relative to the elevated area of the basement. Specifically, the isotherms above the elevated area are convex in shape, while those below the elevated area are concave. There is a temperature equilibrium line between the convex and concave isotherms. The heat flow moves from the depressed area to the uplifted area below the temperature equilibrium line and migrates in an opposite direction above the line. On this base, this study conducted the inversion of geothermal temperature fields in typical areas with thin, moderately thick, and thick cap rocks. The results indicate that, at the depth of 3000–6000 m, areas with thin cap rocks (igneous rock zone in the coastal area of Fujian) mainly host moderate- to low-temperature hydrothermal resources; areas with moderately thick cap rocks (Yuezhong Depression) have the geothermal temperature ranging between 100 °C and 200 °C and may develop moderate- to high-temperature hydrothermal resources and hot dry rocks (HDRs), with the former superimposing on the latter; and areas with thick cap rocks (onshore Beibuwan Basin) have a geothermal temperature of 120‒220 °C, and contains mainly moderate- to high-temperature hydrothermal resources and HDRs. Therefore, it is recommended that the evaluation, exploitation, and utilization of deep geothermal resources be carried out according to the burial depth of the temperature equilibrium line and the specific demand for geothermal resources.http://www.sciencedirect.com/science/article/pii/S2666759223000549Fujian-Guangdong-Hainan areaCap rockNumerical simulationGeothermal field inversionResource enrichment |
| spellingShingle | Zongquan Hu Ying Zhang Yan Zeng Controlling effects of cap rocks on the formation of deep geothermal resources Energy Geoscience Fujian-Guangdong-Hainan area Cap rock Numerical simulation Geothermal field inversion Resource enrichment |
| title | Controlling effects of cap rocks on the formation of deep geothermal resources |
| title_full | Controlling effects of cap rocks on the formation of deep geothermal resources |
| title_fullStr | Controlling effects of cap rocks on the formation of deep geothermal resources |
| title_full_unstemmed | Controlling effects of cap rocks on the formation of deep geothermal resources |
| title_short | Controlling effects of cap rocks on the formation of deep geothermal resources |
| title_sort | controlling effects of cap rocks on the formation of deep geothermal resources |
| topic | Fujian-Guangdong-Hainan area Cap rock Numerical simulation Geothermal field inversion Resource enrichment |
| url | http://www.sciencedirect.com/science/article/pii/S2666759223000549 |
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