Abstract: A downhole steering tool is disclosed. The steering tool includes a rotatable shaft, a substantially non-rotating tool body deployed about the shaft, and a plurality of force application members deployed on the steering tool body. The steering tool further includes a bendable section deployed in the steering tool body. The bendable section is disposed to bend preferentially relative to the steering tool body under an applied bending load. The use of a steering tool body having a bendable section tends to advantageously reduce bending stresses in the steering tool body during use. Moreover, tools embodying this invention may be suitable for higher dogleg severity applications.

Abstract: A connector assembly for connecting with a rotatable shaft is provided. The connector assembly includes a mating sleeve threadably coupleable about the shaft and a center sleeve sized and shaped for deployment between the shaft and the mating sleeve. The center sleeve includes pluralities of splines formed on inner and outer surfaces thereof. The splines on the inner surface of the center sleeve are engageable with splines on the outer surface of the shaft and the splines on the outer surface of the center sleeve are engageable with splines on the inner surface of the mating sleeve. Exemplary embodiments of this invention are useful in downhole tools to reduce make-up torque requirements of the mating sleeve, and therefore may advantageously increase the cyclic torsional and/or bending load capacity of the shaft, while also increasing the total torsional load capacity of the connection.

Abstract: A drilling assembly and an eccentric, adjustable diameter reamer are disclosed. The reamer includes cutter elements mounted on at least a first fixed blade for reaming a previously-formed borehole or for forming a borehole of increased diameter beneath an existing cased borehole. The method and apparatus provide for stabilizing the drilling assembly so that the reamer may be used in back reaming the hole. Retainer means, such as shear pins or spring-biased reciprocating latch members, are provided to prevent premature extension of the reamer's moveable members, including blades and pistons. The shear pins are preferably accessible from the outer surface of the reamer housing so as to expedite field replacement of the shear pins without requiring disassembly of the reamer. The spring-biased latching members repeatedly latch and unlatch so that field replacement is not required, and so that the movable members may be extended and contracted multiple times while the reamer is downhole.

Abstract: The drilling system includes a work string supporting a bottom hole assembly. The work string including lengths of pipe having a non-metallic portion. The work string preferably includes a composite coiled tubing having a fluid impermeable liner, multiple load carrying layers, and a wear layer. Multiple electrical conductors and data transmission conductors may be embedded in the load carrying layers for carrying current or transmitting data between the bottom hole assembly and the surface. The bottom hole assembly includes a bit, a gamma ray and inclinometer instrument package, a steerable assembly, an electronics section, a transmission, and a power section for rotating the bit. It may or may not include a propulsion system. The drilling system may be a gravity based drilling system that does include a propulsion system. Various motive means may be provided, such as gravity, to apply weight on the bit.

Abstract: A steering assembly includes upper and lower tubular housings connected by a universal joint. An angle cam is disposed on the end of the lower housing and projects into the upper housing. A plurality of wedge members extend axially from the upper housing and into engagement with the angle cam. Drive trains are connected to the wedge members to move the wedge members toward and away from the angle cam so as to pivot the lower housing at the universal joint and change the angle and azimuth of the lower housing with respect to the upper housing. The lower housing is connected to a bearing pack supporting a drill bit such that upon changing the angle and azimuth of the lower housing, the direction of the drilling of the drill bit is also changed. The steering assembly being connected to composite tubing having conductors in the wall thereof for conducting data and commands between the steering assembly and a processor at the surface and for providing power to the steering assembly.

Abstract: A composite flexible torsion bar coupling is used to connect the orbiting rotor of a Moineau-type motor to the concentrically rotating output drive shaft. The two-piece torsion bar coupling is hollow, to allow fluid passage through the rotor. This permits large quantities of fluid flow through the bit without passing all the fluid through the motor. The torsion bar is connected to the rotor at an inside surface adjacent to a power-producing surface of the rotor. This configuration provides the shortest possible coupling distance, thereby considerably reducing the overall length of the motor without decreasing its power output.