Abstract: An improved drill steering apparatus which includes a lower stabilizer assembly mounted on the drill string in close relationship to the drill bit and an upper stabilizer assembly mounted on said drill string at a position spaced above said lower stabilizer assembly. In the preferred form of the invention, the pressure responsive element of the stabilizer assemblies are pressure responsive bladders and the lower or slave bladders have a larger effective pressure area than the upper bladders. In a modified form of the invention, the pressure responsive elements are pistons and the lower stabilizer assembly includes at least one more piston in each ground than the upper stabilizer assembly.

Abstract: An improved well drilling steering tool including a tubular body, an upper stabilizer mounted on the tubular body with a means contained therein for sensing the low side of the well bore and for transmitting hydraulic signals responsive thereto, valving means connected in the tubular body to control the end location for the hydraulic signals from the sensing means, a lower stabilizer mounted on the tubular body close to the drill bit and having means for exerting a transverse thrust to the tubular body responsive to the hydraulic signals received from the sensing means and the valving means, the upper and lower stabilizers are supported on the tubular body by upper and lower floating rings and retaining rings which cause the stabilizers to rotate with the tubular body and allow relative radial movement between the stabilizers and the tubular body and the stabilizers and their mounting rings include passages therebetween to prevent the build-up of materials within the stabilizers which would interfere with the

Abstract: Well bore drilling apparatus has a steering tool operable to stabilize the drill string above the drill bit and to selectively cause a lateral force to be applied to the bit to deflect the drill in a selected direction. The apparatus includes master sensors, in the form of pistons, which sense the lateral force of the drill stem on the low side of the hole and apply fluid pressure to selected slave pistons which are circumferentially spaced above the drill bit to apply lateral thrust in the selected direction. The slave pistons are selected by valves in the apparatus which are opened or closed, as desired, either before running the tool into the well bore or by a wireline manipulator tool while the tool remains in the well bore.

Abstract: The method and apparatus for drilling a well bore and setting a liner therein in which the drill string with a bit and underreamers thereon also includes a liner supported thereon which has a gripping assembly with two sets of gripping elements and a pair of external tapers on the liner each of which coacts with one of the sets of gripping elements, one of which wedges one set of gripping elements into set position responsive to the liner weight and the other of which is spaced from said one a sufficient distance that said one is removed from wedging engagement when said other wedges the other set of gripping elements into set position responsive to upward forces on said liner, and a normally closed bypass around the sealing means on the liner which may be opened responsive to manipulation of the liner to allow cementing of the liner in position within the well bore and the steps of lowering the liner on the drill string as the well bore is being formed, setting the liner, gripping assembly and sealing means,

Abstract: An improved drive train for a progressive cavity device is disclosed. The progressive cavity device has a rotor, a stator, means for fluid to enter between said stator and rotor, and means for fluid to exit therefrom. The rotor is adapted to roll with respect to the stator. The improved drive train comprises means attached to the rotor, for rotation substantially about a single axis, whereby the rolling of said rotor and the rotational motion about said single axis are directly connected and are at different speeds. At least a portion of said means attached to the rotor is aligned with the true center of the rotor.