| 摘要 |
<p>A down-hole reaming apparatus 100 having two integral blade stabilisers 130, 140 each orientated in a different rotational directions and each having cutting structures located on the blades 110, 120. An impeller 150 and a flow accelerator 160 are located between the stabilisers. The impeller consists of a plurality of radial blades arranged helically around the longitudinal axis of the impeller. The flow accelerator has a variable diameter profile along its longitudinal axis formed by a first region having a increasing diameter and a second region having a decreasing diameter which is longer than the first region. An integral blade stabiliser includes a plurality of blades and a cutting section on each blade, comprising a wedge with a plurality of cutters located on an end of the blade with a retention section holding the wedge in place.</p> |
