为研究特厚煤层开采卸压瓦斯储集区动态演化规律，采用3DEC 数值模拟软件，分析了采动覆岩应力及位移分布规律，研究了卸压瓦斯储集区演化特征，提出了卸压瓦斯储集区位置判别方法，并在试验工作面高位钻孔瓦斯抽采进行了实践。结果表明：特厚煤层开采后，覆岩垮落带高度49.5 m，裂隙带高度104 m。工作面侧卸压区范围内关键层失稳后，其下方形成卸压瓦斯储集区。卸压瓦斯储集区划分为3 类：①关键层处于弯曲下沉带，其下方形成高位储集区；②关键层处于裂隙带，砌体梁下方形成中位储集区；③关键层处于垮落带，悬臂梁下方形成低位储集区。储集区形态及面积与其上方控制关键层状态密切相关，控制关键层破断前，面积持续上升，低位储集区形态呈矩形，中位和高位储集区形态呈半椭圆形，拓展至三维形态呈矩形截面环体和椭圆截面半椭球体；破断后面积快速下降，之后随覆岩来压呈现周期性变化，低位储集区形态呈梯形，中位储集区形态呈三角形，高位储集区形态呈半椭圆形，拓展至三维形态呈矩形截面环体、三角形截面环体和椭圆截面半椭球体。现场将高位钻孔的终孔位置布置在中位储集区范围，进行了抽采验证，单孔最大抽采浓度34.5%，平均抽采浓度16.8%，抽采后上隅角瓦斯体积分数0.55%，瓦斯抽采效果良好，说明据此方法布置高位钻孔具有合理性。

In order to study the dynamic evolution law of the pressure relief gas reservoir in the mining of extra-thick coal seams, the 3DEC numerical simulation software was used to analyze the stress and displacement distribution law of the overburden rock caused by mining, and the evolution characteristics of the pressure relief gas reservoir were studied, and the pressure relief gas was proposed. The method of discriminating the location of the reservoir area, and the practice of gas drainage in high-position boreholes at the test working face. The results show that: after the extra-thick coal seam is mined, the height of the overburden caving zone is 49.5 m, and the height of the fracture zone is 104 m. After the key strata in the pressure relief zone on the working face side loses stability, a pressure relief gas reservoir is formed below it. Pressure relief gas reservoir areas are divided into three categories: ①The key layer is in the bent subsidence zone, and the high-level reservoir is formed below it; ②The key layer is in the fracture zone, and the middle-level reservoir is formed under the masonry beam; ③The key layer is in the fracture zone. In the collapse zone, a low-level storage area is formed under the cantilever beam. The shape and area of the reservoir are closely related to the state of the control key layer above. Before the control key layer is broken, the area continues to increase. The shape of the low-level reservoir is rectangular, and the shape of the middle and high-level reservoir is semi-elliptical, expanding to a three-dimensional shape. It is a rectangular cross-section ring body and an elliptical cross-section semi-ellipsoid body; the area decreases rapidly after breaking, and then changes periodically with the pressure of the overlying rock. The low-level reservoir is trapezoidal, the middle-level reservoir is triangular, and the high-level reservoir is shaped like a trapezoid. The shape is a semi-ellipse, and the three-dimensional shape is expanded to a rectangular cross-section ring, a triangular cross-section ring and an elliptical cross-section semi-ellipsoid. The location of the final hole of the high-level borehole was arranged in the range of the middle reservoir area, and the drainage verification was carried out. The maximum drainage concentration of a single hole was 34.5%, the average drainage concentration was 16.8%, and the upper corner gas concentration after drainage was 0.55%, The gas drainage effect is good, indicating that the arrangement of high-level drilling holes according to this method is reasonable.