水力冲孔物理模拟试验及其卸压增透效果研究

发布时间：2018-05-11 03:14

本文选题：水力冲孔 + 卸压增透　；参考：《煤炭科学技术》2017年06期

【摘要】：为了研究水力冲孔卸压增透机理,以有效解决单一松软低渗煤层抽采困难的问题,利用自主研发的水力冲孔物理模拟试验系统,开展了不同转速条件下的水力冲孔试验,并对比冲孔前后煤层瓦斯抽采过程中瓦斯压力演化规律,分析冲孔作用对煤层瓦斯抽采达标范围的影响。研究结果表明:随冲孔转速提高,冲孔出煤量、冲孔孔洞等效半径及冲孔卸压半径增大,导致相同抽采时间条件下抽采达标范围增大;冲孔卸压半径在地应力较大的方向较大,在地应力较小的方向较小,冲孔卸压半径为冲孔孔洞等效半径的1.6~2.0倍;在冲孔卸压半径以内,抽采初期瓦斯压力下降速率明显提高,在冲孔卸压半径以外,抽采初期瓦斯压力下降速率影响不明显,抽采一段时间后,瓦斯压力下降速率明显提高;瓦斯抽采达标区域形状与冲孔卸压范围形状相似,在垂直于钻孔截面上近似为椭圆。
[Abstract]:In order to study the mechanism of pressure relief and antireflection of hydraulic punching holes and to effectively solve the problem of extraction of single soft and low permeability coal seams, hydraulic punching tests under different rotational speeds were carried out by using the self-developed physical simulation test system for hydraulic punching holes. The evolution law of gas pressure in the process of gas extraction before and after punching is compared, and the influence of punching on the reach range of gas drainage in coal seam is analyzed. The results show that with the increase of the speed of punching, the amount of coal produced, the equivalent radius of the punching hole and the pressure relief radius of the punching hole increase, which results in the increase of the standard range of the extraction under the same extraction time, and the larger the pressure relief radius of the punching hole in the direction of larger in-situ stress. In the direction of smaller in-situ stress, the pressure relief radius of the punching hole is 1.6 ~ 2.0 times of the equivalent radius of the punching hole, and within the pressure relief radius of the punching hole, the gas pressure drop rate increases obviously in the early stage of drainage, and beyond the pressure relief radius of the punching hole, The decrease rate of gas pressure is not obvious in the early stage of gas extraction. After a period of extraction, the rate of gas pressure drop is obviously increased, and the shape of the area reaching the standard of gas extraction is similar to that of the relief range of punching hole, which is approximately elliptical in perpendicular to the section of borehole.
【作者单位】：河南能源化工集团研究院有限公司;重庆大学煤矿灾害动力学与控制国家重点实验室;
【基金】：国家科技重大专项资助项目(2016ZX05044) 河南省创新型科技人才队伍建设工程资助项目(164100510024) 国家自然科学基金重点资助项目(51434003)
【分类号】：TD712.6

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