为了更好地揭示顺层钻孔瓦斯抽采过程中有效抽采半径的变化及抽采叠加效应对抽采效果的影响，基于孔隙−裂隙双重介质的假设，建立三维煤层瓦斯气固耦合模型。基于所建理论模型，以山西亚美大宁能源有限公司2901工作面为工程背景，利用COMSOL软件开展煤层瓦斯抽采数值模拟，分析了有效抽采半径随抽采时间的变化规律，结合现场试验结果验证了数值模拟结果的准确性。研究了多钻孔抽采叠加效应机理，分析了布孔间距和抽采负压对抽采叠加效应的影响。研究结果表明：有效抽采半径的变化幅度随抽采时间逐渐减缓，并趋于稳定，两者呈幂函数关系，函数表达式为：R=0.24t^0.59；采用瓦斯储量法进行现场测定，煤层瓦斯有效抽采半径的数值模拟结果与现场试验结果之间的平均误差为7.7%，验证了所建三维煤层瓦斯气固耦合模型的合理性；同一区域内布置多个顺层钻孔同时进行瓦斯抽采时，区域内存在叠加效应形成复合抽采达标区域，钻孔间距越小，钻孔控制区域内的煤层叠加效应越明显，相同抽采时间下瓦斯压力降幅越快，抽采负压对叠加效应几乎没有影响；以系数k=P_m/P_c作为抽采叠加效应的评判指标，在确定单孔抽采有效半径R的情况下，顺层瓦斯抽采时叠加效应的影响范围可达2.2R，研究结果为煤矿顺层钻孔的合理布局提供了理论依据。

In order to better reveal the change of effective extraction radius and the influence of extraction superposition effect on the extraction effect in the process of coal seam gas extraction, a three-dimensional coal seam gas-solid coupling model is established based on the assumption of pore-fracture dual medium. Based on the theoretical model, 2901 working face of Shanxi Yamei Daning Energy Co., Ltd. is taken as the technical background, and numerical simulation of coal seam gas extraction is carried out by using COMSOL software, which analyzes the change rule of effective extraction radius with extraction time, and verifies the accuracy of numerical simulation results by combining with the results of on-site test. The mechanism of the superposition effect of multi-drilling extraction was studied, and the influence of hole spacing and negative pressure on the superposition effect of extraction was analyzed. The results show that: the change amplitude of the effective extraction radius gradually slows down with the extraction time and tends to stabilize, and the two are in a power function relationship, with the functional expression R=0.24t^0.59; the average error between the numerical simulation results of the effective extraction radius of coal seam gas and the results of the field test is 7.7% when the field test is carried out by using the gas storage method, which verifies the rationality of the three-dimensional gas-solid coupling model of coal seam gas. The reasonableness of the three-dimensional gas-solid coupling model of coal seam gas is verified. When several downgradient boreholes are arranged in the same area for gas extraction at the same time, there is a superposition effect in the area to form a composite extraction reach area; the smaller the spacing of the boreholes, the more obvious is the superposition effect of the coal seams in the area under the control of the boreholes, and the faster is the decrease of the gas pressure at the same extraction time, and there is almost no influence of the negative pressure on the superposition effect of extraction; With the coefficient k=P_m/P_c as the evaluation index of the superposition effect of extraction, in the case of determining the effective radius R of single-hole extraction, the influencing range of the superposition effect of gas extraction in the well can be up to 2.2R, and the results of the study provide a theoretical basis for the rational design of downhole drilling in coal mines.