Abstract: A system and method for assembling a communication system in a drilling system configured to drill a borehole in an earthen formation. The communication system has a first antenna assembly and a second antenna assembly that are communicatively coupled together. The method includes attaching a first antenna to the first drill string component and attaching a second antenna to a second antenna assembly. The communication system is configured such that the first drill string component and the second drill string component are communicatively coupled together.

Abstract: A system and method for pressure locking a downhole tool in position during a drilling operation includes rotating the drill string to drill a borehole. A fluid is pumped through a passage of a drill string in the downhole direction wherein fluid undergoes a pressure drop at the downhole end of the drill string such that fluid in the passage of the drill string is under higher pressure than the fluid outside the drill string. While fluid is flowing, an uphole portion of the downhole tool, such as a MWD tool, is exposed to the higher pressure fluid and a downhole portion of the downhole tool to the lower pressure fluid, thereby seating the downhole tool in a receptacle member attached to the drill string in the passage. Ceasing flow easily eliminates the locking force created by differential pressure allowing the tool to be retrieved.

Abstract: A system for damping vibration in a drill string can include a magnetorheological fluid valve assembly having a supply of a magnetorheological fluid. A remanent magnetic field is induced in the valve during operation that can be used to provide the magnetic field for operating the valve so as to eliminate the need to energize the coils except temporarily when changing the amount of damping required. The current to be supplied to the coil for inducing a desired magnetic field in the valve is determined based on the limiting hysteresis curve of the valve and the history of the magnetization of the value using a binary search methodology. The history of the magnetization of the valve is expressed as a series of sets of current and it resulting magnetization at which the current experienced a reversal compared to prior values of the current.

Abstract: A strain sensor assembly is configured to detect one or more of forces applied to a structure having a recess. The strain sensor can include at least a pair of opposed strain gauge members that extend from the support member. Each strain gauge member defines a support portion carried by the support member and a biasing portion. The support portion includes at least one strain gauge sensor. The biasing portion is configured to bias against a wall of the recess of the structure when the strain sensor assembly is disposed in the recess. The strain sensor assembly is configured such that the at least a pair of strain gauge members form an interference fit with the wall of the recess when the strain sensor assembly is inserted in the recess.

Abstract: This disclosure includes a current sensor configured to detect a signal current in a drilling system component of a drilling system, a telemetry system, and a method for detecting a signal current. The current sensor includes a magnetic body, at least one field coil positioned on the magnetic body, and at least one drive coil positioned on the magnetic body. The at least one field coil configured to detect a first magnetic field that passes within the magnetic body that is induced by the signal current carried by the drill system component when the current sensor is positioned in proximity to the drilling system component. The at least one drive coil configured to generate a second magnetic field. The current sensor is configured to modulate the second magnetic field such the at least one field coil detects the modulated magnetic field.

Abstract: A drilling system including a drill string, an EM telemetry assembly, and an electric contact assembly that defines an electrical connection with the drill string. The electric contact assembly permits a portion of the EM tool to slide along a portion of the drill string during drill string assembly.

Abstract: A high pressure seal assembly includes a seal element that moves in response to an increase in pressure.

Abstract: A system and method for monitoring underground drilling in which vibration is monitored by creating a model of the drill string using finite element techniques or finite difference techniques and (i) predicting vibration by inputting real time values of operating parameters into the model, and then adjusting the model to agree with measured vibration data, (ii) predicting the weight on bit and drill string and mud motor speeds at which resonance will occur, as well as when stick-slip will occur, so that the operator can avoid operating regimes that will result in high vibration, (iii) determining vibration and torque levels along the length of the drill string based on the measured vibration and torque at one or more locations, (iv) determining the remaining life of critical components of the drill string based on the history of the vibration to which the components have been subjected, and (v) determining the optimum drilling parameters that will avoid excessive vibration of the drill string.

Abstract: A system, rotary pulser, and method is disclosed to transmit information from a downhole location to a surface.

Abstract: A rotary steering apparatus for a drill string in which a bending section induces a bend in a portion of the bottom hole assembly of the drill string by using the rotation of the drive shaft that drives the drill bit during normal drilling, while operating at a reduced or zero drilling mud flow rate, to drive a reduction gear that rotates a nut or cam so as to place a tension tube into tension. The tension tube abuts a flexible housing and places the flexible housing in compression. The flexible housing has a local weakening formed in it that causes it to preferentially bend in a predetermined direction. Compression in the flexible housing causes the housing to bend, which bends a portion of the bottom hole assembly so as to alter the direction of drilling. Rotation of the drive shaft at reduced or zero mud flow rate also causes the drive shaft to drive rotation of a second reduction gear the output of which rotates the bent portion of the bottom hole assembly thereby altering its tool face angle.

Abstract: An apparatus and method for damping vibration, especially torsional vibration due to stick-slip, in a drill string, Sensors measure the instantaneous angular velocity of the drill string at one or more locations along the length of the drill string. One or more vibration damping modules are also spaced along the length of the drill string. When torsional vibration above a threshold is detected, the damping module imposes a reverse torque on the drill that dampens the torsional vibration. The reverse torque can be created by imparting a frictional resistance to the rotation of the drill string. The frictional resistance can be created externally, by extending friction pads from the damping module so that they contact the bore hole wall and drag along the bore hole as the drill string rotates, or internally by anchoring a housing mounted on the drill string to the wall of the bore hole and then imposing frictional resistance on a fluid, such as a magnetorheological fluid, flowing within the drill string.

Abstract: An apparatus for measuring the bending on a drill bit operating down hole in a well may comprise at least three pockets circumferentially spaced equidistantly around the drill collar of the drill string to which the drill bit is attached. Four strain gauges are equidistantly circumferentially spaced around each of the pockets so as to form first and second sets of strain gauges. The strain gauges in the first set are connected into one Wheatstone bridge while the gauges in the second set are connected in a second bridge. Each of the strain gauges 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 bending on the drill bit.

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 pulser includes a rotor having blades that are capable of imparting a varying obstruction to the flow of drilling fluid through stator passages, depending on the circumferential orientation of the rotor, so that rotation of the rotor by a motor generates the encoded pressure pulses. A spring biases the rotor toward the stator so as to reduce the axial gap between the rotor and stator. When the pressure drop across the rotor becomes excessive, such as when increasing drilling fluid flow rate or switching from a high data rate to a low data rate transmission mode, the spring bias is overcome so as to increase the axial gap and reduce the pressure drop across the rotor, thereby automatically reducing the thrust load on the bearings.

Abstract: This disclosure includes a current sensor configured to detect a signal current in a drilling system component of a drilling system, a telemetry system, and a method for detecting a signal current. The current sensor includes a magnetic body, at least one field coil positioned on the magnetic body, and at least one drive coil positioned on the magnetic body. The at least one field coil configured to detect a first magnetic field that passes within the magnetic body that is induced by the signal current carried by the drill system component when the current sensor is positioned in proximity to the drilling system component. The at least one drive coil configured to generate a second magnetic field. The current sensor is configured to modulate the second magnetic field such the at least one field coil detects the modulated magnetic field.

Abstract: A drilling system including a drill string, an EM telemetry assembly, and an electric contact assembly that defines an electrical connection with the drill string. The electric contact assembly permits a portion of the EM tool to slide along a portion of the drill string during drill string assembly.

Abstract: A method of optimizing underground drilling in which the Specific Energy, such as the Mechanical Specific Energy, is determined at a plurality of weight on bits and drill bit rotary speeds. The drilling operation is optimized by drilling at the operating conditions, including weight on bit and drill bit rotary speed, at which the standard deviation in Mechanical Specific Energy is a minimum. The drilling operation is monitored by determining the Mechanical Specific Energy and changing the operating parameters if the standard deviation in the Mechanical Specific Energy exceeds a predetermined value.

Abstract: A system, apparatus and method for monitoring a drilling operation includes receiving a signal via a first pair of antennas positioned on a surface of the earthen formation. The signal received by the first pair of antennas has a first signal characteristic. The method includes receiving the signal via a second pair of antennas positioned on the surface at a different location than that of the first pair of antennas. The signal received by the second pair of antennas has a second signal characteristic. The method includes identifying which of the first signal characteristic and the second signal characteristic of the signal received by the respective first and second pairs of antennas is a preferred signal characteristic. The method can include decoding the signal received by one of the first and second pairs of antennas that has received the signal with the preferred signal characteristic.

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 system and method for monitoring underground drilling in which vibration is monitored by creating a model of the drill string using finite element techniques or finite difference techniques and (i) predicting vibration by inputting real time values of operating parameters into the model, and then adjusting the model to agree with measured vibration data, (ii) predicting the weight on bit and drill string and mud motor speeds at which resonance will occur, as well as when stick-slip will occur, so that the operator can avoid operating regimes that will result in high vibration, (iii) determining vibration and torque levels along the length of the drill string based on the measured vibration and torque at one or more locations, (iv) determining the remaining life of critical components of the drill string based on the history of the vibration to which the components have been subjected, and (v) determining the optimum drilling parameters that will avoid excessive vibration of the drill string.

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.