| 摘要 |
<p>A safety trip button (12) is described for a weight-set downhole tool. The button operates between the tool body (36) and a sleeve (34) of the tool, locking them initially together. When the tool reaches a selected formation (44) in a well bore, the button engages the formation (44) which unlocks the body and sleeve. The button is kept in the unlocked position by virtue of the formation while the tool is set. The button prevents premature setting of the tool and finds application on weight set tools such as packers and circulation tools.</p> |
