Abstract: Preferred methods and systems generate a control input based on a periodically-varying characteristic associated with the rotation of a drill string. The periodically varying characteristic can be correlated with the magnetic tool face and gravity tool face of a rotating component of the drill string, so that the control input can be used to initiate a response in the rotating component as a function of gravity tool face.

Abstract: A preferred method for acquiring information during an underground drilling operation includes providing a sensing device capable of acquiring information concerning the underground drilling operation from a down-hole location on a selective basis in response to an input from the surface, and drilling for a first period of time. The preferred method also includes sending the input to the sensing device after drilling for the first period of time, and drilling during a second period of time while acquiring the information using the sensing device.

Abstract: A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable between an extended position wherein the actuating arm can contact a surface of the bore and thereby exert a force on the housing of the guidance module, and a retracted position.

Abstract: A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.

Abstract: A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable between an extended position wherein the actuating arm can contact a surface of the bore and thereby exert a force on the housing of the guidance module, and a retracted position.

Abstract: A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.

Abstract: A rotary pulser for transmitting information to the surface from down hole in a well by generating pressure pulses encoded to contain information. The pressure pulses travel to the surface where they are decoded so as to decipher the information. The pulser includes housing containing a stator forming passages through which drilling fluid flows on its way to the drill bit, a rotor, and a replaceable wear sleeve enclosing the rotor. The rotor has blades that are capable of imparting a varying obstruction to the flow of drilling fluid through the stator passages depending on the circumferential orientation of the rotor, so that rotation of the rotor by a motor generates the encoded pressure pulses.

Abstract: A preferred method for acquiring information during an underground drilling operation includes providing a sensing device capable of acquiring information concerning the underground drilling operation from a down-hole location on a selective basis in response to an input from the surface, and drilling for a first period of time. The preferred method also includes sending the input to the sensing device after drilling for the first period of time, and drilling during a second period of time while acquiring the information using the sensing device.

Abstract: A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable between an extended position wherein the actuating arm can contact a surface of the bore and thereby exert a force on the housing of the guidance module, and a retracted position.

Abstract: A method and apparatus for transmitting information to the surface from down hole in a well in which a pulser is incorporated into the bottom hole assembly of a drill string that generates pressure pulses encoded to contain information concerning the drilling operation. The pressure pulses travel to the surface where they are decoded so as to decipher the information. The pulser includes a stator forming passages through which drilling fluid flows on its way to the drill bit. The rotor has blades that obstruct the flow of drilling fluid through the passages when the rotor is rotated into a first orientation and that relieve the obstruction when rotated into a second orientation, so that oscillation of the rotor generates the encoded pressure pulses. An electric motor, under the operation of a controller, drives a drive train that oscillates the rotor between the first and second orientations.

Abstract: A method and apparatus for determining the concentration of a constituent in a fluid by directing a beam of light into the fluid and sensing the intensity of components of the light emerging from the fluid at various wavelengths. The light emerging from the fluid can be light that has been attenuated by absorption or induced by fluorescent radiation. The effect of scattering on the light is minimized by normalizing the component intensities, which are then applied to an algorithm incorporating weighting factors that weighs the influence that the intensity at each wavelength has on the determination of the concentration of the constituent for which the algorithm was developed. The algorithm is developed by a regression analysis based upon a plurality of known mixtures containing various concentrations of the constituent of interest.

Abstract: Drill string sections are provided comprising internal passages that may be used to facilitate the electrical or hydraulic connection of multiple devices, such as sensors, arranged at spaced apart positions along the length of the drill sections. Methods of manufacturing the drill string sections are also provided, wherein the internal passages are formed by a first passage, a second passage, and a connecting passage therebetween.

Abstract: An apparatus for measuring the weight and torque on a drill bit operating down hole in a well. The apparatus comprises at least three pockets circumferentially spaced equidistantly around the drill collar of the drill string to which the drill bit is attached. Eight strain gages are equidistantly circumferentially spaced around each of the pockets so as to form first and second sets of strain gages. The strain gages in the first set are connected into one Wheatstone bridge while the gages in the second set are connected in a second bridge. Each of the strain gages that are oriented similarly within each of the pockets are connected in series within a single leg of a bridge so that the output voltage of the bridge is unaffected by bending in the drill string. The output of first bridge is used to determine the weight on the drill bit while the output of the second bridge is used to determine the torque on the drill bit.

Abstract: A method and apparatus for determining the concentration of a constituent in a fluid by directing a beam of light into the fluid and sensing the intensity of components of the light emerging from the fluid at various wavelengths. The light emerging from the fluid can be light that has been attenuated by absorption or induced by fluorescent radiation. The effect of scattering on the light is minimized by normalizing the component intensities, which are then applied to an algorithm incorporating weighting factors that weighs the influence that the intensity at each wavelength has on the determination of the concentration of the constituent for which the algorithm was developed. The algorithm is developed by a regression analysis based upon a plurality of known mixtures containing various concentrations of the constituent of interest.

Abstract: A method of making a stator for a helicoidal pump/motor formed by a network of fibers encapsulated in an elastomer. The core is formed by laying up elastomeric preforms into helical grooves formed in a mandrel and wrapping an elastomeric sheet around helical projections formed in the mandrel. Successive strips of calendered rubber/wire cloth are then laid up into the grooves so as to fill the grooves, which are then wrapped in another layer of calendered rubber/wire cloth. The assembly is then filament wound with reinforcing cords and compression cured so as to bond the elastomeric components into a unitary element. The assembly is then placed in the stator housing and additional elastomer injected into the annular passage between the stator housing and the assembly. The completed assembly is then further cured so that the injected and previously cured elastomers bond to form a unitary structure having good strength and heat transfer capabilities.

Abstract: A rotatable steerable drill string in which guidance module controls the direction of the drilling. A magnetorheological fluid in the module supplies pressure to pistons that apply forces to the wall of the bore and thereby alter the direction of the drilling. The pressure applied by the magnetorheological fluid is regulated by valves that apply a magnetic field to the fluid so as to increase or decrease its fluid shear strength thereby controlling the actuation of the pistons and the direction of the drilling.

Abstract: A rotatable steerable drill string in which guidance module controls the direction of the drilling. A magnetorheological fluid in the module supplies pressure to pistons that apply forces to the wall of the bore and thereby alter the direction of the drilling. The pressure applied by the magnetorheological fluid is regulated by valves that apply a magnetic field to the fluid so as to increase or decrease its fluid shear strength thereby controlling the actuation of the pistons and the direction of the drilling.

Abstract: A system for cooling electronic components in the downhole assembly of a drill string through which a drilling fluid flows. The cooling system includes a thermoelectric cooler that conducts heat from the electronic component to a first heat transfer surface of a thermal conductor. The heat received by the first heat transfer surface is transferred within the thermal conductor to a second heat transfer surface that then transfers the heat to a housing. The housing transfers the heat to the drilling fluid flowing over the housing. To ensure good conductive heat transfer between the electronic component, the thermoelectric cooler, the thermal conductor and the housing, and to absorb shock, vibration and differential thermal expansion, these components are supported on a spring mechanism that generates a force that biases the electronic component against the thermoelectric cooler, the thermoelectric cooler against the thermal conductor and the thermal conductor against the housing.

Abstract: A coupling that makes electrical connections across a joint joining adjacent tubular members, such as drill pipe sections in a drill string. A male sleeve, made from an electrical insulating material, is attached to the male end of one pipe section. A number of axially spaced apart male contact members, such as ring segments or buttons, are formed on the outside surface of the male end. The male contact members are spring biased radially outward. Each of the male contact members is radially displaced from the axial centerline of the pipe section by a progressively increasing amount. A female sleeve, also made from an electrical insulating material, is attached to the female end of the other pipe section. A number of female contact members, such as ring segments or buttons, are formed on the inside surface of the female end. Each of the female contact members is radially displaced from the axial centerline of the pipe section by a progressively increasing amount.

Abstract: A method and apparatus for communicating with a device downhole in a well, such as a bottom hole assembly in a drill string. Pressure pulses, such as those generated by the pistons of the mud pump, are transmitted through the drilling mud to a pressure pulsation sensor in the bottom hole assembly. The pressure pulsation sensor features a piezoceramic element that generates a varying voltage signal in response to the received pressure pulsations. The pressure pulsation sensor also has electronic components that allow it to analyze a characteristic of the pressure pulsations, such as their frequency. Based on its analysis of the pressure pulsations, the sensor can decipher a command from the surface, for example, that directs the steering of a steerable drill string, or that can determine whether the mud pumps are operating.