| 摘要 |
<p>A tool for enlarging well bores, comprising a tubular housing (1) a cutter (6) extending outwardly of the housing and having a cutting edge (6A, B, C) engaging a well bore wall, and a passageway (8) through the housing for delivery of pressurised fluid, the housing wall being apertured (9, 10) to direct fluid from the passageway in a direction lateral of the housing and at generally the same level on the housing as said cutting edge.</p> |
