Abstract： In order to study the problem of high gas emission under the condition of high strength mining in Tashan Coal Mine, the ground L-type drilling project was carried out in Tashan Coal Mine of Datong Mining Area. The L-type well adopts three-hole body structure. In the first operation, the φ444.5 mm drill bit was drilled to 60 m below the bedrock surface, and the φ339.7 mm×9.65 mm surface casing was cemented. The second opening is guided by φ216 mm drill bit, the φ311 mm drill bit is drilled to 480 m, and the φ244.5 mm×8.94 mm technical casing is used for cementing. The φ216 mm bit was drilled to the target 866 m, and the φ168.28 mm×8.94 mm technical casing was drilled. The results can explore new ways for gas control in fully mechanized caving face with large mining height in Datong Coal Mine Group.
