| 摘要 |
A system 20 for use in a subterranean wellbore 22 includes an earth boring bit 40 on a lower end of a drill string 26, and an inflatable packer system. The packer system includes a pressure activated inlet valve 68 that regulates pressurized fluid from within the drill string 26 to the packer 62 for inflating the packer 62. The inlet valve 68 opens above a pressure used for drilling and includes a piston 72 and spring 74 disposed in a cylinder 70; the spring 74 provides a biasing force against the piston 72 and positions the piston 72 between the annulus and an inlet port to the packer 62. When inflated, the packer 62 extends radially outward from the drill string 26 and into sealing engagement with an inner surface of the wellbore 22. |
