| 摘要 |
A downhole apparatus for diverting fluid flow out of a work string comprising a top sub 10 connected to a piston housing 20 and an upper piston 70, a middle piston 80 and a lower piston 90 are positioned within the housing as is a locating sleeve 110 which has a j-track 115. A locating pin 45 connected to the piston housing is located within the j-track. A spring housing 40 containing spring 55 is connected to a lower end of the piston housing. A ported housing 50, having a plurality of ports 130 is connected to the lower end of the spring housing and a lower sub 60 is connected to a lower end of the ported housing. A flow tube 100 having a restriction 105 is located within the central bores of the ported, spring and piston housings and is connected to the locating sleeve. Fluid flow through the restriction creates an increase in fluid pressure causing the movement of the pistons. The pistons move the flow tube between various locations within the apparatus. In one location, the flow tube prevents fluid flow to the annulus while in another location the flow tube allows fluid flow to be diverted into the annulus. The locating sleeve and j-track allow the flow tube to be selectively retained at the various locations within the apparatus with fluid flow through the apparatus being used to cycle the apparatus between diverting fluid flow to the annulus and forcing fluid flow down the work string. |
