吉宁矿CO_(2)气相压裂条件下抽采半径时变规律

Time-varying rule of extraction radius under CO_(2) gas phase fracturing in Jining mine

针对低渗厚煤层瓦斯抽采难度大,抽采效率低的问题,以华晋焦煤吉宁矿为工程背景,运用CO_(2)气相压裂技术对煤层进行增透,增大煤层的渗透性。采用数值模拟,构造吉宁矿2#煤层煤体抽采半径本构模型,运用COMSOL数值模拟软件对CO_(2)气相压裂增透前后抽采半径进行模拟,并通过与现场实测的华晋吉宁煤矿2#煤层原始煤体瓦斯抽采半径和CO_(2)气相压裂增透煤体的瓦斯抽采半径进行对比分析验证CO_(2)气相压裂技术的增透效果。现场工程实践表明:华晋吉宁煤矿2#煤层原始煤体的抽采半径为2.5 m,CO_(2)气相压裂增透煤体的抽采半径为5.5 m,是原始煤体抽采半径的2.2倍,增透效果显著,误差在10%以内。

In view of the difficulty and low efficiency of gas extraction in low permeability and thick coal seam,CO_(2) gas fracturing technology is used to enhance the permeability of coal seam with the engineering background of Huajin coking coal Jining mine.By using numerical simulation,a constitutive model of the extraction radius of 2#coal seam in Jining Mine is constructed,and COMSOL numerical simulation software is used to simulate the extraction radius before and after CO_(2) gas fracturing with enhanced reflection.The effect of CO_(2) gas fracturing is verified by comparing the gas extraction radius of the original coal body and the gas extraction radius of the CO_(2) gas fracturing anti-reflection coal body measured in the field.Field engineering practice shows that the extraction radius of the original coal body in the 2#coal seam of Huajin Jining Coal Mine is 2.5 m,and the extraction radius of the anti-reflection coal body by CO_(2) gas fracturing is 5.5 m,which is 2.2 times of the original coal body,and the anti-reflection effect is remarkable.Error<10%.