Characteristics of igneous rocks and their significance in hydrocarbon accumulation in Block C of Santos Basin, SE Brazil
Santos Basin is characterized by multiple phases of magmatic events and widespread distribution of igneous rocks, which have significant affect of hydrocarbon accumulation. Taking Block C of Santos Basin as a typical and representative example, this paper focused on the characteristics of igneous ro...
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| Format: | Article |
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Editorial Department of Bulletin of Geological Science and Technology
2023-03-01
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| Series: | 地质科技通报 |
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| Online Access: | https://dzkjqb.cug.edu.cn/en/article/doi/10.19509/j.cnki.dzkq.tb20210489 |
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| author | Jian Zhao Jie Zhang Junfeng Zhao Kangxu Ren Chaofeng Wang Yuan Guo |
| author_facet | Jian Zhao Jie Zhang Junfeng Zhao Kangxu Ren Chaofeng Wang Yuan Guo |
| author_sort | Jian Zhao |
| collection | DOAJ |
| description | Santos Basin is characterized by multiple phases of magmatic events and widespread distribution of igneous rocks, which have significant affect of hydrocarbon accumulation. Taking Block C of Santos Basin as a typical and representative example, this paper focused on the characteristics of igneous rocks and their roles in hydrocarbon accumulation through the analysis of igneous rock petrology, geochronology, petrogeochemistry, and gas isotopes. In Block C, at least two main stages of magma events were developed: Aptian magma (122.8±0.6-110.8±0.6 Ma) and Santonian-Campanian magma (84.2±0.7-77.4±0.4). The Aptian magma is dominated by eruptive rocks and has experienced dozens of eruptions, accompanied by several layers of subvolcanic rocks. In comparison, Santonian-Campanian magma is distributed in a relatively random pattern. The multipulse eruption of Aptian magma formed an igneous rock-coquinas complex of more than 600 meters in thickness, inducing a local paleohigh in Itapema Formation. This directly caused the trap crest to shift and contributed to the development of high-quality carbonate deposition in Barra Velha Formation. Before the eruption of Aptian magma, the north flank of Block C was paleohigh, where a particular scale of microbial carbonate reservoirs was anticipated to develop in the Barra Velha Formation as well. These carbonate reservoirs were favorable for hydrocarbon accumulation. The later Santonian-Campanian intrusions also impact carbonate reservoirs through hydrothermal fluid circulation and contact metamorphism. Meanwhile, a large amount of associated CO2 accumulated in the trap led to a high GOR (gas oil ratio) and high CO2 content and changed the fluid composition through the extraction process.A CO2 gas reservoir with condensed oil was eventually formed in the current crest in Block C, as proven by drilled well A.Another pool with high CO2 content is also expected in its north flank, to be demonstrated in the future. |
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| id | doaj.art-5eb829a5abf142989950f28e2fb6a07c |
| institution | Directory Open Access Journal |
| issn | 2096-8523 |
| language | zho |
| last_indexed | 2024-03-07T15:50:18Z |
| publishDate | 2023-03-01 |
| publisher | Editorial Department of Bulletin of Geological Science and Technology |
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| series | 地质科技通报 |
| spelling | doaj.art-5eb829a5abf142989950f28e2fb6a07c2024-03-05T02:55:09ZzhoEditorial Department of Bulletin of Geological Science and Technology地质科技通报2096-85232023-03-01422606810.19509/j.cnki.dzkq.tb20210489dzkjtb-42-2-60Characteristics of igneous rocks and their significance in hydrocarbon accumulation in Block C of Santos Basin, SE BrazilJian Zhao0Jie Zhang1Junfeng Zhao2Kangxu Ren3Chaofeng Wang4Yuan Guo5China National Oil and Gas Exploration & Development Corporation, Beijing 100034, ChinaChina National Oil and Gas Exploration & Development Corporation, Beijing 100034, ChinaChina National Oil and Gas Exploration & Development Corporation, Beijing 100034, ChinaChina National Oil and Gas Exploration & Development Corporation, Beijing 100034, ChinaPetroChina Hangzhou Research Institute of Geology, Hangzhou 310023, ChinaChina National Oil and Gas Exploration & Development Corporation, Beijing 100034, ChinaSantos Basin is characterized by multiple phases of magmatic events and widespread distribution of igneous rocks, which have significant affect of hydrocarbon accumulation. Taking Block C of Santos Basin as a typical and representative example, this paper focused on the characteristics of igneous rocks and their roles in hydrocarbon accumulation through the analysis of igneous rock petrology, geochronology, petrogeochemistry, and gas isotopes. In Block C, at least two main stages of magma events were developed: Aptian magma (122.8±0.6-110.8±0.6 Ma) and Santonian-Campanian magma (84.2±0.7-77.4±0.4). The Aptian magma is dominated by eruptive rocks and has experienced dozens of eruptions, accompanied by several layers of subvolcanic rocks. In comparison, Santonian-Campanian magma is distributed in a relatively random pattern. The multipulse eruption of Aptian magma formed an igneous rock-coquinas complex of more than 600 meters in thickness, inducing a local paleohigh in Itapema Formation. This directly caused the trap crest to shift and contributed to the development of high-quality carbonate deposition in Barra Velha Formation. Before the eruption of Aptian magma, the north flank of Block C was paleohigh, where a particular scale of microbial carbonate reservoirs was anticipated to develop in the Barra Velha Formation as well. These carbonate reservoirs were favorable for hydrocarbon accumulation. The later Santonian-Campanian intrusions also impact carbonate reservoirs through hydrothermal fluid circulation and contact metamorphism. Meanwhile, a large amount of associated CO2 accumulated in the trap led to a high GOR (gas oil ratio) and high CO2 content and changed the fluid composition through the extraction process.A CO2 gas reservoir with condensed oil was eventually formed in the current crest in Block C, as proven by drilled well A.Another pool with high CO2 content is also expected in its north flank, to be demonstrated in the future.https://dzkjqb.cug.edu.cn/en/article/doi/10.19509/j.cnki.dzkq.tb20210489santos basinblock cigneous rockstructure inversioncarbonate sedimentaryco2 contentgeological reservoir modelbrazil |
| spellingShingle | Jian Zhao Jie Zhang Junfeng Zhao Kangxu Ren Chaofeng Wang Yuan Guo Characteristics of igneous rocks and their significance in hydrocarbon accumulation in Block C of Santos Basin, SE Brazil 地质科技通报 santos basin block c igneous rock structure inversion carbonate sedimentary co2 content geological reservoir model brazil |
| title | Characteristics of igneous rocks and their significance in hydrocarbon accumulation in Block C of Santos Basin, SE Brazil |
| title_full | Characteristics of igneous rocks and their significance in hydrocarbon accumulation in Block C of Santos Basin, SE Brazil |
| title_fullStr | Characteristics of igneous rocks and their significance in hydrocarbon accumulation in Block C of Santos Basin, SE Brazil |
| title_full_unstemmed | Characteristics of igneous rocks and their significance in hydrocarbon accumulation in Block C of Santos Basin, SE Brazil |
| title_short | Characteristics of igneous rocks and their significance in hydrocarbon accumulation in Block C of Santos Basin, SE Brazil |
| title_sort | characteristics of igneous rocks and their significance in hydrocarbon accumulation in block c of santos basin se brazil |
| topic | santos basin block c igneous rock structure inversion carbonate sedimentary co2 content geological reservoir model brazil |
| url | https://dzkjqb.cug.edu.cn/en/article/doi/10.19509/j.cnki.dzkq.tb20210489 |
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