| 摘要 |
<p>Downhole appts. comprises: (a) a housing for connecting to a drill pipe; (b) a mandrel sliding in the housing; (c) a stinger for positioning in the housing and allowing pumping of fluid therethrough; and (d) a latch for latching the stinger to the housing when the stinger is moved downwardly in the housing. The appts. also includes: (i) means for biasing the mandrel port towards an unlatched position, in which the biasing means is a shoulder on the mandrel, another shoulder on the housing, and a spring between the shoulders; and (ii) means for sealing between the stinger and the mandrel, in which, because of the latching engagement between the latch fingers and the stinger, the seal is constantly engaged when fluid is pumped through the stinger. The latch has a latch finger pivoting on the mandrel for latching engagement with a groove on the stinger. The latch finger has a lug for extending into the latching groove when in the latched position. A piston is provided on the mandrel as a portion thereof for providing a downward force on the mandrel to help hold it in the latched position when pressure is applied to the piston, which is in fluid communication with the central opening through the stinger. One or more pistons may be used. The stinger is pref. attached to a coiled tubing string, but may be positioned in the drill pipe in other ways as well. Also claimed is a method of pumping fluid into a drill pipe.</p> |
