Abstract: A method of drilling a borehole from a surface location with a drill string, and a system for implementing the method are provided. The method includes a rotary mode that involves rotating the drill string at a rotary mode rotation rate in order to drill the borehole for a rotary interval, an orientation mode that involves rotating the drill string at an orientation mode rotation rate and transitioning the rotation of the drill string from the orientation mode rotation rate to a surface stop orientation, and maintaining the drill string at a surface fixed orientation in order to drill the borehole in a directional mode for a directional interval. The surface stop orientation is selected based upon a predicted relationship between the surface stop orientation and a toolface stop orientation.

Abstract: A method of drilling a borehole from a surface location with a drill string, and a system for implementing the method are provided. The method includes a rotary mode that involves rotating the drill string at a rotary mode rotation rate in order to drill the borehole for a rotary interval, an orientation mode that involves rotating the drill string at an orientation mode rotation rate and transitioning the rotation of the drill string from the orientation mode rotation rate to a surface stop orientation, and maintaining the drill string at a surface fixed orientation in order to drill the borehole in a directional mode for a directional interval. The surface stop orientation is selected based upon a predicted relationship between the surface stop orientation and a toolface stop orientation.

Abstract: Apparatus is provided for introducing a consistent series of small and localized rotary impacts to a PDC bit during drilling, to improve PDC drill bit performance. Rotary impact supplements the nominal torque supplied by the rotary drive thereby avoiding lockup and potentially damaging energy storage in the drill string following windup, should the bit slow or hang up when drilling in difficult formations. The apparatus comprises a rotary hammer which is rotated about a bit shaft's anvil, preferably by a drilling fluid driven turbine. As the hammer rotates, potential energy is built up. When the hammer and anvil connect, the energy is released into the bit shaft and thus into the bit, increases its instantaneous torque and allows it to more effectively cut through difficult formations.

Abstract: An improved coiled tubing directional drilling method comprises: providing a bent housing which is rotatably coupled to the coiled tubing, rotating the drill bit, and rotating the bent housing. Apparatus for achieving the method comprises: a rotary connection between the coiled tubing and the bent housing and means for rotating the bent housing relative to the coiled tubing and to the drill bit. A fluid pressure-operated clutch enables alternate rotation and locking of the bent housing. Preferably, a first downhole motor rotates the drill bit and a second downhole motor rotates the bent housing through the clutch or alternately a speed reducer permits the bent housing to contra-rotate slowly under reactive torque developed by the rotating drilling bit.

Abstract: Apparatus is provided for introducing a consistent series of small and localized rotary impacts to a PDC bit during drilling, to improve PDC drill bit performance. Rotary impact supplements the nominal torque supplied by the rotary drive thereby avoiding lockup and potentially damaging energy storage in the drill string following windup, should the bit slow or hang up when drilling in difficult formations. The apparatus comprises a rotary hammer which is rotated about a bit shaft's anvil, preferably by a drilling fluid driven turbine. As the hammer rotates, potential energy is built up. When the hammer and anvil connect, the energy is released into the bit shaft and thus into the bit, increases its instantaneous torque and allows it to more effectively cut through difficult formations.

Abstract: An improved coiled tubing directional drilling method comprises: providing a bent housing which is rotatably coupled to the coiled tubing, rotating the drill bit, and rotating the bent housing. Apparatus for achieving the method comprises: a rotary connection between the coiled tubing and the bent housing and means for rotating the bent housing relative to the coiled tubing and to the drill bit. A fluid pressure-operated clutch enables alternate rotation and locking of the bent housing. Preferably, a first downhole motor rotates the drill bit and a second downhole motor rotates the bent housing through the clutch or alternately a speed reducer permits the bent housing to contra-rotate slowly under reactive torque developed by the rotating drilling bit.

Abstract: A fail-safe tubular receiving member for use in combination with a latch assembly to longitudinally support and rotationally orient the latch assembly in a wellbore. The latch assembly includes at least one outwardly biased, radially movable latch member which is receivable within a bore of the receiving member. A first recessed area and a second recessed area, accessible from the first recessed area, are defined by the bore. The first recessed area defines a first increased radial distance and is configured so that upon longitudinal alignment of the latch member and the first recessed area, the latch member moves radially outward for receipt in the first recessed area to support the latch assembly longitudinally such that longitudinal movement of the latch assembly relative to the receiving member further downhole is prevented.