摘要 |
A carriage (4) carrying drilling heads (6) is lowered through a well into the conduit and moved by telecontrol to the location (3) presenting the leakage. There, the drilling heads (6) are advanced radially outwardly and the drills (10) drill holes (12) into the wall (11) of the conduit. The carriage (4) is locked by movable pressure plates (13, 14). After drilling into the wall (11), a sealing product is injected through the hollow drills (10) into the ground (2) surrounding the conduit. This product solidifies and forms a sealing mass having the shape of mushroom at the vicinity of the holes (12), and seals the leakage. Radially moving shields (9) prevent the sealing product from flowing into the conduit. Then, the drills (10) and the drilling heads (6) are withdrawn and the carriage is pulled backwards. Hence, it is possible to arrange a sealing mass on the outer side of a non practicable conduit so that the sealing material bears against the conduit under the action of the ground pressure. |