Device for forming process-controlled horizontal filter well utilized e.g. for ground water drainage in brown coal open mining, has post-cutting head with borehole conduit connected with borehole outlet and chipped pipe by swing bearing

摘要

The device has a chipped annular space and an expansion head that is mounted to a drill pipe (11). The expansion head is provided with a drilling fluid distributor and comprises a pre-cutting head (12) and a post-cutting head (13). The post-cutting head is connected with a protective pipe string (14) with an inner lying filter rod (4) by a swing bearing. The post-cutting head is provided with a small borehole conduit (16) that is connected with a small borehole outlet and a chipped pipe (17) by a swing bearing.