Abstract: An acoustic isolator for attenuating through-tool acoustic signals comprises a plurality of u-shaped link members, where each link member has two sets of ears. A plurality of yoke members are adapted to fit between cooperating sets of ears. A plurality of pins connect the plurality of u-shaped link members to the plurality of yoke members for providing limited flexural compliance. The isolator may be made from metallic and/or composite materials.

Abstract: An acoustic logging apparatus comprises a drill collar conveyed on a drilling tubular in a borehole within a formation. At least one transmitter is disposed in the drill collar. The transmitter includes at least one magnetostrictive actuator cooperatively coupled by a flexure ring to a piston for converting a magnetostrictive actuator displacement into a related piston displacement for transmitting an acoustic signal in the formation.

Abstract: An acoustic logging apparatus comprises a drill collar conveyed on a drilling tubular in a borehole within a formation. At least one transmitter is disposed in the drill collar. The transmitter includes at least one magnetostrictive actuator cooperatively coupled by a flexure ring to a piston for converting a magnetostrictive actuator displacement into a related piston displacement for transmitting an acoustic signal in the formation.

Abstract: An acoustic isolator for attenuating through-tool acoustic signals comprises a plurality of u-shaped link members, where each link member has two sets of ears. A plurality of yoke members are adapted to fit between cooperating sets of ears. A plurality of pins connect the plurality of u-shaped link members to the plurality of yoke members for providing limited flexural compliance. The isolator may be made from metallic and/or composite materials.

Abstract: An acoustic isolator for attenuating through-tool acoustic signals comprises a plurality of u-shaped link members, where each link member has two sets of ears. A plurality of yoke members are adapted to fit between cooperating sets of ears. A plurality of pins connect the plurality of u-shaped link members to the plurality of yoke members for providing limited flexural compliance. The isolator may be made from metallic and/or composite materials.

Abstract: The present invention provides a measurement-while-drilling (MWD) system having a downhole computer and multiple downhole sensors. Relatively large amounts of basic or “raw” data are measured by downhole sensors, and these data are processed within a downhole computer to be reduced to parameters of interest, which may be utilized to control the drilling operation by downhole devices, stored downhole, telemetered to the surface, or both. The measurements may be correlated downhole with stored reference data thereby providing additional information pertaining to the drilling operation. Downhole depth correlation between downhole measured parameters may be made by utilizing surface determined or downhole determined borehole depth.

Abstract: The present invention provides a measurement-while-drilling (MWD) system having a downhole computer and multiple downhole sensors. Relatively large amounts of basic or "raw" data are measured by downhole sensors, and these data are processed within a downhole computer to be reduced to parameters of interest, which may be utilized to control the drilling operation by downhole devices, stored downhole, telemetered to the surface, or both. The measurements may be correlated downhole with stored reference data thereby providing additional information pertaining to the drilling operation. Downhole depth correlation between downhole measured parameters may be made by utilizing surface determined or downhole determined borehole depth.

Abstract: The present invention provides a drilling system for directional drilling of boreholes. The system contains a drill string having a drill bit driven by a positive displacement mud motor. Sensors placed at selected locations in the drill string continually measure various downhole operating parameters, including the differential pressure across the mud motor, rotational speed of the mud motor, torque, temperature, pressure differential between the fluid passing through the mud motor and the annulas between the drill string and the borehole, and temperature of the circulating fluid. A downhole control circuit having a microprocessor and nonvolatile memory processes signals from these sensors and transmits the processed data uphole to a surface control unit via a suitable telemetry system. The surface control unit is programmed to operate the drilling system or aid an operator to control the drilling operations in any number of modes in response to the information provided by the various sensors.

Abstract: A method for directional drilling of a well with a motor and drill bit. A tubular housing is secured to the lower end of the motor with the housing having a first surface with an axis angularly disposed relative to the axis of the tubular housing. A second tubular housing has a surface engagable with the first surface and is angularly disposed relative to the axis of the second tubular housing with the extent of the engagement of the first and second surfaces determining the angular position of the axis of the second tubular housing relative to the axis of the first tubular housing. The extent of the engagment of the surfaces is selectively adjustable by shims. A first angular stabilizer is carried with a drill bit which is rotatably mounted with a drive means including universal joints. The apparatus is secured to a tubing string with a drill bit and lowered into the bore hole with the apparatus actuated by application of tubing weight with direction being controlled by rotation of the drill string.

Abstract: Apparatus for effecting a change in the direction of a downhole rotary drilling tool comprises a bent housing disposed between the bottom end of a downhole motor and a tubular housing connected to the drilling tool. The bent housing is angularly adjustable relative to the motor housing and the connecting housing is provided with an eccentric external surface upon which an annular eccentric stabilizer is adjustably mounted. In a modification, a second annular eccentric stabilizer is mounted on the upper portion of the motor housing. Selective angular adjustment of the eccentric stabilizers relative to their mounting housings, coupled with angular adjustment of the bent housing effects any desired shift in angular position of the rotary drilling tool to effect a desired change in the direction of the drilling with a minimum of side wall interference.

Abstract: Apparatus for effecting a minute change in the direction of a downhole rotary tool comprises an eccentric cylindrical surface formed on the housing of a downhole motor or a member connected between the motor and the tool, which is received within an eccentric bore of a stabilizer housing, the periphery of which snugly engages the walls of, for example, the newly drilled well bore. Selective angular adjustment of the eccentric stabilizer housing relative to the eccentric surface provided on or adjacent to the motor housing effects a desired shift in angular position of the rotary tool to effect a desired change in the direction of the selected activity, such as drilling.

Abstract: An apparatus is provided for effecting a change in direction of a rotary drill bit relative to a work string. Two tubular components incorporated into the work string have a rotationally adjustable connection for angularly displacing the drill bit axis relative to the tubing string. One embodiment has the connection between a housing for the shaft of the drill bit and the housing for the motor which drives the shaft. The connection comprises a pair of cylindrically disposed interengagable surfaces formed on the adjacent ends of the motor shaft housing and the drill bit housing, which have axes that are slightly angularly displaced from the housing axes.

Abstract: A downhole device which can be incorporated into the tubular drill string transmitting torque to the drilling bit and concurrently providing an indication of the torque transmitted. A telescopically interrelated housing and mandrel have their non-telescoped ends connected with the rotating power source and the drilling bit. A resilient torque transmitting mechanism, such as a helical spring, is mounted between the mandrel and the annular housing to transmit torque between such elements but at the same time produce an angular displacement of one element with respect to the other. A fluid passage is provided through the bores of the telescopically interrelated mandrel and the housing and communicating apertures are formed in the adjacent ends of such bores to produce a variable orifice whose pressure drop due to the flow changes as a function of the angular displacement of the housing and mandrel, hence as a function of the torque being transmitted.

Abstract: A mud screen for installation between any two selected ends of interconnected pipes, such as a drill pipe string, comprises a supporting collar anchored in the selected threaded connection of the drill pipe string and a screen support mounted on such collar and secured thereto by one or more releasing devices. An apertured inverted conical screen is supported by the screen support in transverse relationship to the pipe bore. A bridging element is secured across the screen support and defines a mounting for an upstanding post which functions as a manual handle and also defines a fishing neck at its upper end for downhole retrieval.

Abstract: A method of drilling a subterranean well utilizing a downhole drilling apparatus is disclosed. The apparatus has a driven rotary drive shaft and a relatively fixed tubular housing circumjacent the drive shaft, with the housing having an annular upwardly facing bearing surface at an angle to a longitudinal axis of the housing and an annular sealing surface facing downwardly at an angle to the axis and axially spaced above the upwardly facing bearing surface. The method includes the steps of securing the drilling apparatus to the lower end of a string of drill pipes suspended in the well with the longitudinal axis of the housing coincident with the longitudinal axis of the string of drill pipe. Thereafter, the drill bit is secured to the lower end of the drive shaft, and fluid is pumped through the drilling apparatus to rotate the drive shaft and the bit.

Abstract: A bearing supports a rotatable shaft in a fluid environment. The bearing can be utilized to support a drive shaft connected to a drill bit in a downhole drilling apparatus. The drive shaft extends through a housing in which drilling fluid is flowing. Preferably, the bearing includes an inner elastomeric sleeve and an outer rigid sleeve attached to the interior side wall of the housing. The drive shaft has a wear sleeve attached for rotation therewith. The wear sleeve is rotatably received in the bearing inner sleeve. The inner sleeve is relatively short as compared with the drive shaft and absorbs radial loads imposed on the drive shaft. The bearing is lubricated by a portion of the drilling fluid in the housing which flows between the exterior side wall of the wear sleeve and the interior side wall of the inner sleeve.

Abstract: An apparatus is provided for applying pressure to a fluid seal positioned between a reservoir of a first fluid, such as lubricating fluid, and a source of a second fluid under pressure, such as a drilling fluid in a downhole drilling apparatus. A piston is positioned in a cavity which is in fluid communication with the first fluid reservoir. The piston sealably and slidably engages the side walls of the cavity. A spring moves the piston in a direction to increase the pressure of the first fluid to a value which exceeds the pressure value of a second fluid. Thus, the second fluid is prevented from passing through the fluid seal and contaminating the first fluid.

Abstract: A fluid pressure actuated by-pass valve and relief valve are positioned between a source of fluid under pressure and the hollow interior of a rotor in a fluid pressure actuated downhole drilling motor. The valve includes a hollow mandrel with an inlet opening at one end and an outlet opening at the other end connected to the rotor interior and slidably received in a movable sleeve. Fluid pressure at a first predetermined value moves the mandrel into the sleeve to block the inlet opening such that the fluid by-passes the valve and flows between the stator and the rotor to rotate a bit. Fluid pressure at a higher second predetermined value moves the sleeve relative to the mandrel to expose the inlet opening and relieve the fluid pressure on the rotor and the stator. The movement of the sleeve exposes a greater surface area thereof to the fluid pressure such that a spring moves the sleeve back to block the inlet opening only at an intermediate third predetermined fluid pressure value.

Abstract: A fluid pressure actuated by-pass and relief valve are utilized in a fluid pressure actuated downhole drilling apparatus. The valve is normally closed such that fluid under pressure is directed between a rotor and a stator to rotate a drill bit. When the fluid pressure reaches a predetermined value, the valve is actuated to direct the flow to the hollow interior of the rotor to protect the rotor and the stator from damage due to excessive torque loading. The relief valve is of the sleeve type which can become stuck in the open position due to contaminents in the fluid. In the open position, the pressure drop across the valve will be insufficient to close the valve and the drill bit will not be rotated. A screen is positioned between the outlet of the valve and the interior of the rotor. The screen is then plugged by dropping pieces of plugging material, such as small chips of rubber, down the drill pipe to collect in the screen.

Abstract: A fluid pressure actuated by-pass and relief valve are positioned between a source of fluid under pressure and the hollow interior of a rotor in a fluid pressure actuated downhole drilling motor. The valve includes a hollow mandrel with an inlet opening at one end and an outlet opening at the other end connected to the rotor interior and slidably received in a movable sleeve. Fluid pressure at a first predetermined value moves the mandrel into the sleeve to block the inlet opening such that the fluid by-passes the valve and flows between the stator and the rotor to rotate a bit. Fluid pressure at a higher second predetermined value moves the sleeve relative to the mandrel to expose the inlet opening and relieve the fluid pressure on the rotor and the stator. The movement of the sleeve exposes a greater surface area thereof to the fluid pressure such that a spring moves the sleeve back to block the inlet opening only at an intermediate third predetermined fluid pressure value.