Abstract: Apparatus for controlling a downhole device in a well has a body with a control slot and pin movable in the slot. The slot has a first inactive loop in which the pin can cycle between different idling configurations, and a second active loop in which the pin can move between different configurations which correspond to active and inactive configurations of the downhole device. The pin can be switched between the first and second loops, and can cycle between the different configurations within without switching between the different loops. The slot can be provided on a piston, and the axial movement of the piston in the bore can drive the relative movement of the pin and the slot.

Abstract: A drill string tubular component for use in an oil or gas well, in the form of a tubular having a central bore and a mechanism for mobilizing drill cuttings comprising at least one radial impeller (30) configured to apply radial thrust cuttings passing it, the radial impeller being located between first and second axial impellers (10, 20) configured to apply axial thrust to the fluids in opposite directions. Typically helical components of the first and second axial impellers extend in respective opposite directions, typically toward the radial impeller. Fluids are thus diverted radially away from the outer surface of the tubular component, and thereby enter a more turbulent region of the annulus, there reducing the tendency of the drill cuttings to settle out of suspension.