Petroleum Science >2013, Issue 2: 183-189 DOI: https://doi.org/10.1007/s12182-013-0265-6
Methane in soil gas and its transfer to the atmosphere in the Yakela condensed gas field in the Tarim Basin, Northwest China Open Access
文章信息
作者：Tang Junhong,Wang Guojian,Yin Haoyong and Li Hongjun
作者单位：
College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China;Wuxi Research Institute of Petroleum Geology, Research Institute of Petroleum Exploration and Production, SINOPEC, Wuxi, Jiangsu 214151, China;College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China;College of Materials & Environmental Engineering, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China
投稿时间：2012-10-12
引用方式：Tang, J., Wang, G., Yin, H. et al. Pet. Sci. (2013) 10: 183. https://doi.org/10.1007/s12182-013-0265-6
文章摘要
In this study, by analyzing CH4 concentration and δ13CCH4 in soil-gas profiles, the potentials of CH4 gas transfer from ground to atmosphere were studied at four representative sectors in the Yakela
condensed gas field in the Tarim Basin, Xinjiang, China. These are: 1) the oil–gas interface sector, 2) fault sector, 3) oil–water interface sector, 4) an external area. Variation in CH4 in soil-gas profiles showed that CH4 microseepage resulted from the migration of subsurface hydrocarbon from deep-buried reservoirs to the earth’s surface. It was found that CH4 from deep-buried reservoirs could migrate upwards to the surface through faults, fissures and permeable rocks, during which some CH4 was oxidized and the unoxidized methane remained in the soil or was emitted into the atmosphere. The lowest level of CH4 at the soil-gas profile was found at the CH4 gas-phase equilibrium point at which the CH4 migration upwards from deep-buried reservoirs and the CH4 diffusion downwards from the atmosphere met. The δ13CCH4 and ethane, propane in soil gas exhibited thermogenic characteristics, suggesting the occurrence of CH4 microseepage from deep-buried reservoirs. A linear correlation analysis between CH4 concentrations in soil gas and temperature, moisture, pH, Eh, Ec and particle size of soil indicated that both soil Eh and
soil temperature could affect CH4 concentration in soil gas while soil pH could indirectly influence soil methanotrophic oxidation via impacting soil Eh.
condensed gas field in the Tarim Basin, Xinjiang, China. These are: 1) the oil–gas interface sector, 2) fault sector, 3) oil–water interface sector, 4) an external area. Variation in CH4 in soil-gas profiles showed that CH4 microseepage resulted from the migration of subsurface hydrocarbon from deep-buried reservoirs to the earth’s surface. It was found that CH4 from deep-buried reservoirs could migrate upwards to the surface through faults, fissures and permeable rocks, during which some CH4 was oxidized and the unoxidized methane remained in the soil or was emitted into the atmosphere. The lowest level of CH4 at the soil-gas profile was found at the CH4 gas-phase equilibrium point at which the CH4 migration upwards from deep-buried reservoirs and the CH4 diffusion downwards from the atmosphere met. The δ13CCH4 and ethane, propane in soil gas exhibited thermogenic characteristics, suggesting the occurrence of CH4 microseepage from deep-buried reservoirs. A linear correlation analysis between CH4 concentrations in soil gas and temperature, moisture, pH, Eh, Ec and particle size of soil indicated that both soil Eh and
soil temperature could affect CH4 concentration in soil gas while soil pH could indirectly influence soil methanotrophic oxidation via impacting soil Eh.
关键词
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Soil gas, CH4 concentration, carbon isotope, microseepage, oil reservoir