Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin

Marine–continent transitional facies shale of the Longtan Fm, Upper Permian is an important source rock stratum in the Sichuan Basin. The previous researches on it mainly focus more on source rock evaluation, but less on shale gas accumulation. In this paper, the test and analysis results of Well DY...

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Main Authors: Xusheng Guo, Dongfeng Hu, Ruobing Liu, Xiangfeng Wei, Fubin Wei
Format: Article
Language:English
Published: KeAi Communications Co., Ltd. 2019-06-01
Series:Natural Gas Industry B
Online Access:http://www.sciencedirect.com/science/article/pii/S2352854019300439
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author Xusheng Guo
Dongfeng Hu
Ruobing Liu
Xiangfeng Wei
Fubin Wei
author_facet Xusheng Guo
Dongfeng Hu
Ruobing Liu
Xiangfeng Wei
Fubin Wei
author_sort Xusheng Guo
collection DOAJ
description Marine–continent transitional facies shale of the Longtan Fm, Upper Permian is an important source rock stratum in the Sichuan Basin. The previous researches on it mainly focus more on source rock evaluation, but less on shale gas accumulation. In this paper, the test and analysis results of Well DYS1, the coring well of Longtan Fm were dissected. Combined with the drilling results of its adjacent area, the organic rich shale in the Longtan Fm were studied from the aspects of distribution, geochemical, reservoir, gas-bearing characteristics and roof and floor conditions, and then compared with the shale strata with similar sedimentary background and good shale gas shows. And accordingly, its geological conditions for the formation of Longtan shale gas and its exploration potential were made clear. And the following research results were obtained. First, in the southeastern Sichuan Basin, the organic rich shale of transitional facies of Longtan Fm is developed with a thickness of more than 40 m. It is characterized by high brittle mineral content, high porosity, high total organic carbon (TOC), moderate thermal evolution (Ro) and good gas-bearing property. Therefore, it is geologically favorable for the formation of shale gas. Second, compared with the existing transitional facies shales at home and abroad, the Longtan shale is better in terms of porosity, TOC, Ro, gas content and other key parameters. Third, the type of organic matters is the main reason for the low development degree of organic pores in the Longtan shale. And during its shale gas exploration and selection, the coal seam enriched sections shall be avoided. In conclusion, considering the development degree, interlayer thickness, depth and preservation conditions of organic rich shale comprehensively, the Qijiang–Chishui area is the best exploration area for the transitional facies shale gas of Longtan Fm in the Sichuan Basin. Keywords: Sichuan basin, Late Permian, Longtan Fm, Marine–continental transitional facies, Shale, Total organic carbon, Thermal evolution maturity, Gas content, Shale gas exploration potential
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spelling doaj.art-f6a7d77148a34a5c85fefd1d97a3ef1c2024-03-03T02:58:55ZengKeAi Communications Co., Ltd.Natural Gas Industry B2352-85402019-06-0163198204Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan BasinXusheng Guo0Dongfeng Hu1Ruobing Liu2Xiangfeng Wei3Fubin Wei4Sinopec Exploration Company, Chengdu, Sichuan 610041, ChinaSinopec Exploration Company, Chengdu, Sichuan 610041, ChinaSinopec Exploration Company, Chengdu, Sichuan 610041, ChinaSinopec Exploration Company, Chengdu, Sichuan 610041, ChinaCorresponding author.; Sinopec Exploration Company, Chengdu, Sichuan 610041, ChinaMarine–continent transitional facies shale of the Longtan Fm, Upper Permian is an important source rock stratum in the Sichuan Basin. The previous researches on it mainly focus more on source rock evaluation, but less on shale gas accumulation. In this paper, the test and analysis results of Well DYS1, the coring well of Longtan Fm were dissected. Combined with the drilling results of its adjacent area, the organic rich shale in the Longtan Fm were studied from the aspects of distribution, geochemical, reservoir, gas-bearing characteristics and roof and floor conditions, and then compared with the shale strata with similar sedimentary background and good shale gas shows. And accordingly, its geological conditions for the formation of Longtan shale gas and its exploration potential were made clear. And the following research results were obtained. First, in the southeastern Sichuan Basin, the organic rich shale of transitional facies of Longtan Fm is developed with a thickness of more than 40 m. It is characterized by high brittle mineral content, high porosity, high total organic carbon (TOC), moderate thermal evolution (Ro) and good gas-bearing property. Therefore, it is geologically favorable for the formation of shale gas. Second, compared with the existing transitional facies shales at home and abroad, the Longtan shale is better in terms of porosity, TOC, Ro, gas content and other key parameters. Third, the type of organic matters is the main reason for the low development degree of organic pores in the Longtan shale. And during its shale gas exploration and selection, the coal seam enriched sections shall be avoided. In conclusion, considering the development degree, interlayer thickness, depth and preservation conditions of organic rich shale comprehensively, the Qijiang–Chishui area is the best exploration area for the transitional facies shale gas of Longtan Fm in the Sichuan Basin. Keywords: Sichuan basin, Late Permian, Longtan Fm, Marine–continental transitional facies, Shale, Total organic carbon, Thermal evolution maturity, Gas content, Shale gas exploration potentialhttp://www.sciencedirect.com/science/article/pii/S2352854019300439
spellingShingle Xusheng Guo
Dongfeng Hu
Ruobing Liu
Xiangfeng Wei
Fubin Wei
Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin
Natural Gas Industry B
title Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin
title_full Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin
title_fullStr Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin
title_full_unstemmed Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin
title_short Geological conditions and exploration potential of Permian marine–continent transitional facies shale gas in the Sichuan Basin
title_sort geological conditions and exploration potential of permian marine continent transitional facies shale gas in the sichuan basin
url http://www.sciencedirect.com/science/article/pii/S2352854019300439
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