Abstract: An apparatus and method for detecting lubricant reservoir levels, particularly in bearing sections for downhole mud motors, is revealed. This allows rig personnel to more exactly ascertain the remaining bearing life of the assembly. In one embodiment, the assembly is pulled out of the hole and comprises of a signal source. A hand-held device is placed next to the bearing housing and the location of the strongest signal is a direct measurement of the position of the floating piston in the lubricant reservoir. The rig personnel can then readily obtain a level reading on the fluid level in the reservoir. An alternative design is also revealed where the position of the floating piston is sensed in real-time by receivers mounted at spaced locations in the lubricant reservoir.

Abstract: A downhole motor operated by circulating mud fluid in the wellbore is revealed. The motor has nested rotors and is geared to a bit drive. The motor is a dual-rotor pump that is operated as a motor with mud flow through the rotor housing on end connections. The structures of the rotor housing and the rotors can be made of the same material. An angular offset can be incorporated between the centerline of the output of the motor and the bit drive. In the preferred embodiment, the motor output is through a gear located within a bigger gear connected to the bit so as to provide a speed reducer. The drive between the rotors and the bit can accommodate angular offsets of a predetermined amount for directional drilling. The design is compact and can be used to drill wellbores as small as about 21/2" in diameter, or even smaller.

Abstract: An adjustable bend connection is provided which desirably extends from the power section of a downhole progressing-cavity-type mud motor. The joint is secured internally so that any reverse rotation of the bend housings that may occur does not result in undoing the bend connection. Torque is transmitted separately from the portion of the connection which is used to secure the angle selected. The output shaft from the mud motor extends internally through the bend connection and through the components which retain the preselected angle. A tool can be inserted with the bit removed to secure or to change the angle desired.

Abstract: A mechanism for arients and maintains a key in a sub for guiding directional measurement equipment of a directional drilling assembly with respect to the drillbit. The orienting sub has an outer sleeve which is supported on an inner shoulder in the orienting sub. An inner sleeve which holds the key has an outer wedged profile which follows the shape of the outer sleeve. The outer sleeve can be longitudinally, obliquely, or spirally segmented and has a thread on one end so that a jam nut can be installed to advance the inner sleeve with the key until a wedging action occurs between the inner and outer sleeves and the sub. At that point, the key is oriented without any bores through the wall of the sub. Provisions can be made in the assembly to provide a biasing force on the inner sleeve which holds the key to compensate for vibrational loads on the assembly.