INFLATABLE PACKER ELEMENT FOR USE WITH A DRILL BIT SUB

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).