| 摘要 |
The invention relates to a drilled well (1) which is adapted to extract groundwater. Said well comprises a well pipework (4) installed in a borehole of a rock formation (2) and a filter unit (5) provided at the lower end of the well pipework (4), said filter unit (5) having at least one filter element (6). In a state of extraction, at least the filter element (6) is embedded in a filter bed (9) from a filter material installed in the area of the borehole bottom (7) in the annular space between the filter unit (5) and the borehole walls (8). The invention is characterized in that in order to remove the filter bed (9), at least one guide conduit (10) and at least one flushing conduit (11) are provided. The guide conduit (10) and the flushing conduit (11) extend inside the borehole from the surface of the rock formation (2) at least down to the depth of the filter element (6). The guide conduit (10) comprises at least one conduit opening (13, 14) and the flushing conduit (11) at least one exit opening (12) in the area of the filter bed (9). The exit opening (12) is arranged in relation to the conduit opening (13, 14) in such a manner that the filter material is at least partially entrained by the flushing medium (15) penetrating the flushing conduit (11), enters the guide conduit (10) via the conduit opening (13, 14) and is discharged from the borehole together with the flushing medium (15) through the guide conduit (10). |
