不同吸附性气体抽采过程中煤储层参数演化特征研究

发布时间：2018-02-28 14:07

本文关键词： 瓦斯抽采渗透特性煤储层参数物理模拟　出处：《岩土力学》2017年06期 　论文类型：期刊论文

【摘要】：利用自主研发的多场耦合煤层瓦斯抽采物理模拟试验系统,开展了不同吸附性气体抽采的物理模拟试验,探讨了煤层瓦斯抽采过程中煤储层气压、温度及煤层变形等参数的时空演化规律。结果表明:(1)煤储层气压在抽采前期下降较快并形成以钻孔为中心的气压等值面,距离抽采钻孔越远的区域煤层瓦斯流速越小,气压下降速率越低;(2)气体吸附性越强,抽采过程中的煤储层气压下降速率越低且持续时间越长;(3)煤储层温度的时间演化规律与气压基本一致,在抽采前期有显著的降低,在抽采后期受吸附态气体解吸吸热及热交换作用的影响,煤层温度出现先下降后小幅上升;(4)距离钻孔越近的区域气压下降量越大,煤层温度下降越明显,煤层所受有效应力越大,煤层变形量也越大;(5)抽采气体的吸附性越大,抽采所导致的煤层变形量越大。
[Abstract]:The physical simulation test of different adsorptive gas extraction was carried out by using the self-developed physical simulation test system of multi-field coupled coal seam gas drainage, and the gas pressure of coal reservoir during the process of coal seam gas extraction was discussed. The results show that the gas pressure of the coal reservoir decreases rapidly in the early stage of extraction and forms a pressure isosurface centered on the borehole, and the gas velocity of coal seam is smaller in the area farther away from the drainage borehole. The lower the gas pressure drop rate is, the stronger the gas adsorption is, the lower the gas pressure decline rate and the longer the duration of coal reservoir during extraction and production) the time evolution law of coal reservoir temperature is basically consistent with the pressure pressure, and it decreases obviously in the early stage of extraction and production. At the later stage of extraction, the gas desorption heat absorption and heat exchange of the adsorbed state, the temperature of coal seam decreases first, then rises slightly. (4) the closer the area from the borehole to the hole, the greater the decrease of air pressure, and the more obvious the decrease of coal bed temperature is. The larger the effective stress is, the greater the deformation of coal bed is.
【作者单位】：重庆大学煤矿灾害动力学与控制国家重点试验室;中煤科工集团重庆研究院有限公司;
【基金】：国家自然科学基金(No.51474040;No.51434003;No.51304255)~~
【分类号】：TD712.6

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