| 摘要 |
<p>A distance holder (1) for connection to, and rotation with, a drill string (2) in an earth formation drilling device arranged to supply a jet of abrasive fluid for the purpose of providing a borehole (2) by removing earth formation material through abrasion, comprises a chamber (16) which is essentially rotational symmetric and which is to face the earth formation material, and a jet nozzle (S) arranged for discharging a jet of the abrasive fluid in said chamber. The chamber comprises a deflector (12) positioned in the path of the fluid jet discharged from the jet nozzle.</p> |
