Abstract: A downhole motor may include a power section, a connecting rod assembly, and a drive shaft. The power section may include a stator and a rotor with the rotor configured to rotate eccentrically when a drilling fluid is passed through the stator. The connecting rod assembly operatively connects the rotor of the power section and the drive shaft of the bearing section. The connecting rod assembly may include a housing and a connecting rod. The housing may have a proximal end and a distal end with the proximal end connected to the stator. The connecting rod may include a proximal end including a rigid connection operatively connected to the rotor, a mid flexible rod, and a distal end terminating at or proximate an articulating joint. The drive shaft may be operatively connected to the articulating joint.

Abstract: A downhole motor may include a power section, a connecting rod assembly, and a drive shaft. The power section may include a stator and a rotor with the rotor configured to rotate eccentrically when a drilling fluid is passed through the stator. The connecting rod assembly operatively connects the rotor of the power section and the drive shaft of the bearing section. The connecting rod assembly may include a housing and a connecting rod. The housing may have a proximal end and a distal end with the proximal end connected to the stator. The connecting rod may include a proximal end including a rigid connection operatively connected to the rotor, a mid flexible rod, and a distal end terminating at or proximate an articulating joint. The drive shaft may be operatively connected to the articulating joint.

Abstract: A downhole tool including a purely mechanical stabilizer is disclosed. The stabilizer includes a plurality of fixed blades, each of which includes at least one automatically extendable and retractable piston. In use, a balance of forces determines the radial position of each piston; a hydraulic force urging the piston outward, a spring force urging the piston inward, and external forces acting on the tool (e.g., the force of the borehole wall urging the pistons inward). The stabilizer is further configured such that a balance of forces between the pistons causes the tool to be advantageously automatically and continuously centered during rotation of the tool in the borehole. As such, the invention is suitable for use in boreholes that rapidly change size and shape.

Abstract: A purely mechanical hydraulic control system includes at least one drilling fluid chamber and a hydraulic fluid chamber. A system pressure spring is deployed in one of the drilling fluid chamber(s) between a positioning piston and a system pressure piston. The spring is disposed to pressurize oil in the hydraulic fluid chamber via applying a spring force to the system pressure piston. When the system is actuated (e.g., via turning on the mud pumps), the positioning piston is urged in place against a stop (e.g., a shoulder) thereby compressing the system pressure spring and pressurizing oil in the hydraulic chamber. The invention advantageously converts highly variable drilling fluid pressure to a near constant pressure hydraulic fluid.

Abstract: A purely mechanical hydraulic control system includes at least one drilling fluid chamber and a hydraulic fluid chamber. A system pressure spring is deployed in one of the drilling fluid chamber(s) between a positioning piston and a system pressure piston. The spring is disposed to pressurize oil in the hydraulic fluid chamber via applying a spring force to the system pressure piston. When the system is actuated (e.g., via turning on the mud pumps), the positioning piston is urged in place against a stop (e.g., a shoulder) thereby compressing the system pressure spring and pressurizing oil in the hydraulic chamber. The invention advantageously converts highly variable drilling fluid pressure to a near constant pressure hydraulic fluid.

Abstract: A downhole tool including a purely mechanical stabilizer is disclosed. The stabilizer includes a plurality of fixed blades, each of which includes at least one automatically extendable and retractable piston. In use, a balance of forces determines the radial position of each piston; a hydraulic force urging the piston outward, a spring force urging the piston inward, and external forces acting on the tool (e.g., the force of the borehole wall urging the pistons inward). The stabilizer is further configured such that a balance of forces between the pistons causes the tool to be advantageously automatically and continuously centered during rotation of the tool in the borehole. As such, the invention is suitable for use in boreholes that rapidly change size and shape.

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.