Abstract: A sealing assembly for a downhole device has first (12) and second sealing (22) components which are urged together to make up the assembly such that a first sealing surface (34) on the first component radially presses a lip member (44) on the second component to change the angle of a second sealing surface (45) in the connected assembly. The components are urged together by a driving member (60) which can have screw threads that cooperate with the first component. The lip may be annular and may be formed by an undercut or recess (42) radially inwardly or outwardly of the lip member, allowing the lip member to bend radially inwards into the recess, during insertion of the second sealing component into the first.

Abstract: A housing for a downhole tool, having a fluid vent assembly comprising a port passing through the wall of the housing to transmit fluid through the port when the port is open, a sealing device to seal the port, and a cutting device to disrupt the sealing device and permit transmission of fluid through the port. The cutting device is driven axially through the sealing device without relative rotation between the two. The cutting device has an asymmetric blade to cut a coupon from the sealing device by a gradual and progressive disruption of the closure, typically cutting through only a portion the closure device, so that the coupon cut from the closure device remains attached to the closure device when the closure device is ruptured to open the seal. Typically the downhole tool comprises a downhole pump, and the housing comprises the shroud of the pump.

Abstract: A sealing assembly for a downhole device has first (12) and second sealing (22) components which are urged together to make up the assembly such that a first sealing surface (34) on the first component radially presses a lip member (44) on the second component to change the angle of a second sealing surface (45) in the connected assembly. The components are urged together by a driving member (60) which can have screw threads that cooperate with the first component. The lip may be annular and may be formed by an undercut or recess (42) radially inwardly or outwardly of the lip member, allowing the lip member to bend radially inwards into the recess, during insertion of the second sealing component into the first.

Abstract: A housing for a downhole tool, having a fluid vent assembly comprising a port passing through the wall of the housing to transmit fluid through the port when the port is open, a sealing device to seal the port, and a cutting device to disrupt the sealing device and permit transmission of fluid through the port. The cutting device is driven axially through the sealing device without relative rotation between the two. The cutting device has an asymmetric blade to cut a coupon from the sealing device by a gradual and progressive disruption of the closure, typically cutting through only a portion the closure device, so that the coupon cut from the closure device remains attached to the closure device when the closure device is ruptured to open the seal. Typically the downhole tool comprises a downhole pump, and the housing comprises the shroud of the pump.