Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China
Oil and gas exploration in carbonate rocks was extremely successful in recent years in the Ordovician in Tarim Basin, NW China. Here, we investigate the carbonate reservoirs in the Bachu area of the Tarim Basin through petrological and geochemical studies combined with oil and gas exploration data....
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2015-09-01
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| Series: | Geoscience Frontiers |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1674987115000250 |
| _version_ | 1797758367689605120 |
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| author | Kang Xu Bingsong Yu Hanning Gong Zhuang Ruan Yinglu Pan Yan Ren |
| author_facet | Kang Xu Bingsong Yu Hanning Gong Zhuang Ruan Yinglu Pan Yan Ren |
| author_sort | Kang Xu |
| collection | DOAJ |
| description | Oil and gas exploration in carbonate rocks was extremely successful in recent years in the Ordovician in Tarim Basin, NW China. Here, we investigate the carbonate reservoirs in the Bachu area of the Tarim Basin through petrological and geochemical studies combined with oil and gas exploration data. Geochemical analysis included the major, trace, and rare earth elements; fluid inclusion thermometry; clay mineral characterization; and carbon and oxygen isotopes of the carbonate rocks. Homogenization temperatures of the fluid inclusions of Well He-3 in the Bachu area indicate three groups, 60–80 °C, 90–130 °C, and 140–170 °C, and suggest that the carbonate rocks experienced modification due to heating events. The porosity in the reservoir is defined by fractures and secondary pores, and there is a notable increase in the porosity of the carbonate reservoirs in proximity to magmatic intrusion, particularly approximately 8–10 m from the intrusive rocks. The development of secondary pores was controlled by lithofacies and corrosion by various fluids. We identify supercritical fluids with high density (138.12–143.97 mg/cm3) in the Bachu area. The negative correlations of δ13C (−2.76‰ to −0.97‰) and δ18O (−7.91‰ to −5.07‰) suggest that the carbonate rocks in the study area were modified by high-salinity hydrothermal fluid. The formation of clay minerals, such as illite and montmorillonite, caused a decrease in porosity. Our study demonstrates the effect of magmatic intrusions in modifying the reservoir characteristics of carbonate rocks and has important implications for oil and gas exploration. |
| first_indexed | 2024-03-12T18:29:00Z |
| format | Article |
| id | doaj.art-6dbd1612a27a49daa3f90083c78af98d |
| institution | Directory Open Access Journal |
| issn | 1674-9871 |
| language | English |
| last_indexed | 2024-03-12T18:29:00Z |
| publishDate | 2015-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Geoscience Frontiers |
| spelling | doaj.art-6dbd1612a27a49daa3f90083c78af98d2023-08-02T08:23:49ZengElsevierGeoscience Frontiers1674-98712015-09-016577979010.1016/j.gsf.2015.02.002Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW ChinaKang XuBingsong YuHanning GongZhuang RuanYinglu PanYan RenOil and gas exploration in carbonate rocks was extremely successful in recent years in the Ordovician in Tarim Basin, NW China. Here, we investigate the carbonate reservoirs in the Bachu area of the Tarim Basin through petrological and geochemical studies combined with oil and gas exploration data. Geochemical analysis included the major, trace, and rare earth elements; fluid inclusion thermometry; clay mineral characterization; and carbon and oxygen isotopes of the carbonate rocks. Homogenization temperatures of the fluid inclusions of Well He-3 in the Bachu area indicate three groups, 60–80 °C, 90–130 °C, and 140–170 °C, and suggest that the carbonate rocks experienced modification due to heating events. The porosity in the reservoir is defined by fractures and secondary pores, and there is a notable increase in the porosity of the carbonate reservoirs in proximity to magmatic intrusion, particularly approximately 8–10 m from the intrusive rocks. The development of secondary pores was controlled by lithofacies and corrosion by various fluids. We identify supercritical fluids with high density (138.12–143.97 mg/cm3) in the Bachu area. The negative correlations of δ13C (−2.76‰ to −0.97‰) and δ18O (−7.91‰ to −5.07‰) suggest that the carbonate rocks in the study area were modified by high-salinity hydrothermal fluid. The formation of clay minerals, such as illite and montmorillonite, caused a decrease in porosity. Our study demonstrates the effect of magmatic intrusions in modifying the reservoir characteristics of carbonate rocks and has important implications for oil and gas exploration.http://www.sciencedirect.com/science/article/pii/S1674987115000250Carbonate rocksPetrology and geochemistryOil and gas reservoirTarim BasinNorthwest China |
| spellingShingle | Kang Xu Bingsong Yu Hanning Gong Zhuang Ruan Yinglu Pan Yan Ren Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China Geoscience Frontiers Carbonate rocks Petrology and geochemistry Oil and gas reservoir Tarim Basin Northwest China |
| title | Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China |
| title_full | Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China |
| title_fullStr | Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China |
| title_full_unstemmed | Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China |
| title_short | Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China |
| title_sort | carbonate reservoirs modified by magmatic intrusions in the bachu area tarim basin nw china |
| topic | Carbonate rocks Petrology and geochemistry Oil and gas reservoir Tarim Basin Northwest China |
| url | http://www.sciencedirect.com/science/article/pii/S1674987115000250 |
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