| 摘要 |
A method of sealing an annulus 12 around a drill-pipe 14 when drilling down-hole comprising a deflated packer 16 on a drill pipe, opening one or more ports 18 to said packer using a ball activated valve 20 and circulating drilling fluid 22 to inflate said packer through one or more ports to form a seal in the annulus around the drill-pipe. The method may further comprise the step of closing one or more ports after the packer is inflated. The method may comprise a tool 10 on the drill-pipe that comprises an external body 26 housing the one or more ports to the packer, and an internal sleeve may constitute a ball activated valve. The sleeve may comprise a valve seat 28 configured for the receipt of one or more balls. The method may further comprise ports to allow flow into the annulus above the packer 24. The method may further comprise dropping one or more balls 32 onto the seat valve, and using a pressure gradient to close off the ports once the packer has been inflated. The pressure upstream and downstream the packer may be measured and a control channel is provided through the drill-pipe. |
