| 摘要 |
A down hole well tool (1) comprising a tool unit comprising at least one first fluid conduit (2) and a return fluid conduit (3) in use forming a well annulus between the tool unit and a well bore, and at least one piston (4) dividing the well annulus into well annulus spaces. The piston comprises at least two piston bodies wherein a first piston body (4a) is arranged to rotate with the tool unit and a second piston body (4b) is arranged in a position in between the first piston body and the well bore. The first piston body is arranged to rotate relative the second piston body and first sealing means are arranged in between the first piston body and the second piston body. |
