| 摘要 |
<p>An apparatus includes a counter for tracking and communicating a number of plug drops through a longitudinal bore; a plug element adapted to be dropped into the longitudinal bore; and a valve defining a plug seat to be disposed within the longitudinal bore to catch, the plug element when the plug element is dropped and when the number of plug drops as communicated by the counter exceeds a predetermined number. A method, includes: dropping a plurality of plugs down a longitudinal bore in which a plurality of plug seats are disposed; counting the number of plug drops from within the longitudinal bore; and catching one of the plugs at a preselected one of the plug seats when the number of plug drops exceeds a predetermined number.</p> |
