Abstract: A down hole tool includes a tool body, a fluid cavity, a magnetorheological fluid disposed in the fluid cavity, and an electrical control unit in communication with the MR fluid. The electrical control unit is configured to adjust a viscosity of the MR fluid by varying a magnetic field.

Abstract: A downhole jarring tool includes a mandrel having a small diameter portion and a large diameter portion, a detent cylinder sealingly disposed around the mandrel forming an enclosure, a divider disposed in the enclosure between the mandrel and the detent cylinder, wherein the divider partitions the enclosure into a storage chamber and a metering chamber, and a metering system disposed around the mandrel. A method of applying an impact force using a downhole jarring tool includes moving a mandrel with respect to a detent cylinder by applying an axial force, positioning the mandrel such that a metering system disposed on the mandrel enters a reduced diameter portion of the detent cylinder, transmitting energy to an energy storing component disposed inside the detent cylinder, metering a fluid through the metering system, and accelerating the mandrel with respect to the detent cylinder.

Abstract: A drilling system, including: a drill bit; and a thruster to apply a force to the drill bit. The thruster may include: an inner tubular member disposed within and configured to axially move within an outer tubular member; a thrust piston to transmit a hydraulic force to the inner tubular member, the thrust piston separating an upstream fluid chamber and a downstream fluid chamber between the inner and outer tubular members; at least one pressure switch fluidly connected to the downstream fluid chamber to control flow of a fluid to and from the downstream fluid chamber via at least one fluid inlet and at least one fluid outlet.

Abstract: A down hole tool includes a tool body, a fluid cavity, a magnetorheological fluid disposed in the fluid cavity, and an electrical control unit in communication with the MR fluid. The electrical control unit is configured to adjust a viscosity of the MR fluid by varying a magnetic field.

Abstract: A down hole tool includes a tool body, a fluid cavity, a magnetorheological fluid disposed in the fluid cavity, and an electrical control unit in communication with the MR fluid. The electrical control unit is configured to adjust a viscosity of the MR fluid by varying a magnetic field.

Abstract: A downhole jarring tool includes a mandrel having a small diameter portion and a large diameter portion, a detent cylinder sealingly disposed around the mandrel forming an enclosure, a divider disposed in the enclosure between the mandrel and the detent cylinder, wherein the divider partitions the enclosure into a storage chamber and a metering chamber, and a metering system disposed around the mandrel. A method of applying an impact force using a downhole jarring tool includes moving a mandrel with respect to a detent cylinder by applying an axial force, positioning the mandrel such that a metering system disposed on the mandrel enters a reduced diameter portion of the detent cylinder, transmitting energy to an energy storing component disposed inside the detent cylinder, metering a fluid through the metering system, and accelerating the mandrel with respect to the detent cylinder.

Abstract: A drilling system, including: a drill bit; and a thruster to apply a force to the drill bit. The thruster may include: an inner tubular member disposed within and configured to axially move within an outer tubular member; a thrust piston to transmit a hydraulic force to the inner tubular member, the thrust piston separating an upstream fluid chamber and a downstream fluid chamber between the inner and outer tubular members; at least one pressure switch fluidly connected to the downstream fluid chamber to control flow of a fluid to and from the downstream fluid chamber via at least one fluid inlet and at least one fluid outlet.

Abstract: A down hole tool includes a tool body, a fluid cavity, a magnetorheological fluid disposed in the fluid cavity, and an electrical control unit in communication with the MR fluid. The electrical control unit is configured to adjust a viscosity of the MR fluid by varying a magnetic field.

Abstract: A method for driving a drive pipe into a subsea formation, the method being comprised of the following steps: suspending the drive pipe from a drill string; moving at least one mass in a direction having an upward component and within the drive pipe; accelerating at least one mass relative to the drive pipe, wherein the at least one mass is accelerated within the drive pipe; transferring energy from the accelerated at least one mass to the drive pipe; isolating the drill string from energy from the accelerated at least one mass; and removing a core of formation from within the drive pipe after the transferring.

Abstract: As the outrigger arms of a borehole logging tool are flexed inwardly and outwardly according to the diameter of the borehole opening through which they pass, the corresponding axial displacements of the ends of the arms are controlled to determine the axial positions of the arms relative to the tool. Specifically, as the arm ends move, they are caused to rotate by a cam mechanism. The stiffness of the arms causes the arm ends to rotate in unison, and the exact positions of the arms on the tool are then controlled by the differential movements of the arm ends in the cams.

Abstract: In the several representative embodiments of selectively-operable well bore apparatus disclosed herein for dependently coupling a well tool to a suspension cable, a collapsible assembly of two or more retaining members is arranged within an enclosed chamber and operatively positioned for normally retaining upper and lower tool-support members in a position where they are tandemly coupled or interconnected. In each of the several embodiments of the invention disclosed herein, electrically-responsive securing means normally maintaining the collapsible assembly in its initial position are cooperatively arranged to be selectively failed so as to allow collapse of the retaining assembly should it become necessary to separate the cable from the well tool while it is in a well bore. Provisions are also made for admitting well bore fluids into the enclosed chamber upon collapse of the retaining assembly so as to assure release of the cable even under extreme well bore pressures.

Abstract: A bearing is disclosed that includes a support housing or casing in which is located a body of elastomeric material. A plurality of wear members are positioned to be supported by the body of elastomeric material and to receive the load placed on the bearing. The elastomeric body allows the wear inserts to adjust individually to the load placed on the wear members, which greatly increases the life of the bearing. The wear members are made of a self-lubricating type material, such as one of the fluorocarbons or polyphenylene sulfide resin.