| 摘要 |
<p>A ball activated tool (1) for use in dowhole drilling, said tool being adapted to be mounted in a casing portion of a drill string, in which the tool comprises: a hollow main body (1); outlet port means (5) in the wall of the main body (1) through which fluid can flow transversely of the drill string; a control sleeve (6) slidably mounted in the main body; and, a ball seat arranged at one end of the sleeve (6) to receive a deformable ball (20,104) when the latter is launched down the drill string to activate the tool, which ball seat (100) includes: a deformable annular member (101) , and an abutment (102) which is spaced axially from the annular member (101) by a sufficient distance to allow the abutment (102) and the annular member (101) to co-operate to latch the ball (104) against axial movement inwardly or outwardly of the ball seat (100).</p> |
