| 摘要: |
| 在工程领域,水合物开采及天然气运输过程中普遍存在管道堵塞等问题。为有效地解决天然气输送过程中的堵塞现象,并为油气的高效储存与运输提供重要的理论依据和参考,采用两种不同粒径的多孔介质石英砂混合,在初始压力8 MPa、温度16 ℃条件下进行水合物一次生成实验,一次生成结束后,在不同分解压力下采用恒压升温法对水合物进行分解,分解反应进行150 min 后,稳定至与一次生成相同的初始条件下进行二次生成实验。通过水合物生成过程中反应釜内温度压力变化曲线等,分析不同一次分解压力对水合物二次生成过程及特征指标的影响。实验结果显示,相比一次生成过程,水合物二次生成过程存在明显且稳定的记忆效应。由此得出结论,一次分解压力对水合物二次形成的影响具有临界压力,分解压力为此临界压力时,水合物二次生成速率相对较小且饱和度低,此时记忆效应最弱。这一研究结果可望对自然环境下水合物开采过程中二次生成对管道堵塞的解决、油气的高效储存与运输提供重要支撑。 |
| 关键词: 甲烷水合物 分解压力 二次形成 记忆效应 诱导时间 甲烷消耗量 |
| DOI：10.3969/j.issn.1007-3426.2021.04.010 |
| 分类号: |
| 基金项目:国家自然基金“温度梯度对不同颗粒级配砂土中甲烷水合物分布的控制作用研究”(41661103) |
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| Influence of primary decomposition pressure of hydrate on memory effect |
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Wang Yingmei1,3, Zhang Mengdi1,3, Wu Qingbai2, Zhan Jing2, Zhang Peng2
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1. College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu, China;2. State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Ecological Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu, China;3. Key Laboratory of Complementary Energy Supply System of Biomass Energy and Solar Energy in Gansu Province, Lanzhou University of Technology, Lanzhou, Gansu, China
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| Abstract: |
| In the field of engineering, the problem of pipeline blockage often exists in the process of hydrate exploitation and natural gas transportation. In order to effectively solve the blockage in the process of natural gas transportation and provide an important theoretical basis and a reference for efficient storage and transportation of oil and gas, two kinds of porous media quartz sand with different particle sizes are used to carry out the experiment of hydrate formation at the initial pressure of 8 MPa and temperature of 16 ℃ in this study. After the first formation, the constant pressure and temperature rise method are used for the hydrate decomposed with different pressure and the decomposition reaction is carried out for 150 min, then stabilized to the same initial condition as the primary formation and the secondary formation experiment is carried out. Through the curve of temperature and pressure in the reactor during hydrate formation, the influence of different primary decomposition pressure on secondary formation process and characteristic index is analyzed. The experimental results show that the secondary formation has a significant and stable memory effect compared with the primary formation. It is concluded that the effect of primary decomposition pressure on the secondary formation of hydrate is a critical pressure. When the decomposition pressure is the critical pressure, the secondary formation rate of hydrate is relatively small and the saturation is low, and the memory effect is the weakest. The results of this study are expected to provide an important support for the solution of pipeline blockage caused by the secondary formation of hydrate in the natural environment and the efficient storage and transportation of oil and gas. |
| Key words: methane hydrate decomposition pressure secondary formation memory effect induction time methane consumption |
