Abstract: A down-the-hole vibratory unit for a drilling system includes a casing comprising a fluid inlet. The vibratory unit can also include a plurality of eccentrically weighted rotor assemblies positioned at least partially within the casing and in fluid communication with the inlet. The eccentrically weighted rotor assemblies can be unbalanced relative to a central axis. Additionally, the eccentrically weighted rotor assemblies can be configured to rotate in response to a fluid flow directed thereto to apply centrifugal forces to the casing.

Abstract: There is provided a method for drilling a cased hole and installing a geothermal transfer apparatus. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a drill string into the ground. A retrievable drill bit is operatively connected to the drill string. The cased hole is drilled to a desired depth by rotating and vibrating the drill string into the ground. The retrievable drill bit is retrieved from the cased hole following the drilling of the cased hole to the desired depth. A geothermal transfer apparatus is lowered into the cased hole following the retrieval of the retrievable drill bit. Grouting material may be discharged into the cased hole before or after the drill string is removed from the ground.

Abstract: A vibratory milling machine has a vibratory housing confined to substantially linear reciprocating motion relative to a base, causing a tool carried by the housing to impact a mineral formation or other work piece substantially in a primary milling direction. The vibratory motion may be generated by two or more eccentrically-weighted rotors rotated by a common drive mechanism. The rotors may be arranged in pairs with the rotors of each pair rotating in opposite directions about parallel axes so that lateral oscillations cancel and longitudinal vibrations in the milling direction reinforce one another. In one embodiment, a hydrostatic fluid bearing is provided between the outer surface of each rotor and the housing.

Abstract: A percussion adapter that is driven to generate a percussive axial motion on a wellbore structure. One percussion adapter includes a drive connection to mechanically convert rotational drive to axially directed percussive motion. Another percussion adapter employs a valve that creates back pressure causing axially directed percussive motion. A wellbore tubular connection is also disclosed that transitions torque to resist back off when left hand or right hand torque is applied.

Abstract: The invention relates to a damping device for an output shaft (26) in a gearbox (14, 16), where the gearbox (14, 16) is arranged for rotation of a rotational degree of freedom (Z4,Z5) in a rock-drilling rig (2), and thus for positioning of the same, and where the damping device (18) comprises a brake (38) that acts on the output shaft (26) of the gearbox (14, 16), which brake (38) acts as an oscillation damper for the movement of the output shaft (26), whereby a gearbox (14, 16) with play can be used for applications that require a high degree of precision such as positioning, e.g. measuring a position for a drill hole. The invention also relates to a gearbox (14, 16) and a rock-drilling rig (2) with damping device (18), respectively.

Abstract: Apparatus and methods are described for highly attenuating vibrations of a drillstring assembly while drilling. In one embodiment, vibrations are attenuated by introducing one or more vibration attenuation modules at appropriate assembly locations. For example, vibration attenuation modules may be inserted at locations where vibration energy is expected to be maximal. In one embodiment the vibration attenuation modules include cavities loosely packed with particles of solid material such as sand or metallic powder. In one embodiment, the cavity walls are rough and/or include geometric features that enhance vibration energy transfer to the loosely packed particles in the cavity(ies). The vibration energy is dissipated via friction and inelastic particle-particle and particle-wall collisions that occur as a result of drillstring motion.

Abstract: The present invention relates to drilling apparatus comprising a drill-bit (1) capable of rotary and high frequency oscillatory loading; and control means for controlling applied rotational and/or oscillatory loading of the drill-bit, the control means having adjustment means for varying the applied rotational and/or oscillatory loading, said adjustment means being responsive to conditions of the material through which the drill is passing. The control means is in use provided on the apparatus in a downhole location and includes sensors for taking downhole measurements of material characteristics, whereby the apparatus is operable downhole under closed loop real-time control. The apparatus can determine appropriate loading parameters for the drill-bit in order to achieve and maintain resonance between the drill-bit and the drilled material in contact therewith.

Abstract: Systems and methods cancel or compensate for an echo or noise in borehole communication. The systems and methods provide a downhole tool configured to provide borehole communication via mud pulse telemetry. The downhole tool pulses drilling fluid to generate a first pressure pulse and a second pressure pulse. The first pressure pulse moves upwardly with respect to the downhole component and is encoded with data associated a downhole measurement. A sensor is electrically connected to and in communication with the downhole tool. The first sensor is adapted to detect a characteristic of the second pressure pulse in the drilling mud. A ideal pressure pulse or a correction pressure pulse is generated by a downhole tool or a mud pulse modulator to reduce or cancel noise of the second pressure pulse.

Abstract: Vibrational apparatus capable of providing a vibrational output, said apparatus comprising or including an assembly having a shuttle capable of shuttling between complementary structures, at least one of which complementary structures provides the vibrational output, the arrangement being characterised in that there is a drive to rotate the shuttle and there are magnetic interactions between the rotating shuttle and the complementary structures such that interactions with each complementary structure, and the phasing of the complementary structures relative to the shuttle, alternating magnetic results in the shuttling movement of the shuttle.

Abstract: Apparatus and methods are described for highly attenuating vibrations of a drillstring assembly while drilling. In one embodiment, vibrations are attenuated by introducing one or more vibration attenuation modules at appropriate assembly locations. For example, vibration attenuation modules may be inserted at locations where vibration energy is expected to be maximal. In one embodiment the vibration attenuation modules include cavities loosely packed with particles of solid material such as sand or metallic powder. In one embodiment, the cavity walls are rough and/or include geometric features that enhance vibration energy transfer to the loosely packed particles in the cavity(ies). The vibration energy is dissipated via friction and inelastic particle-particle and particle-wall collisions that occur as a result of drillstring motion.

Abstract: Drill rods and systems for use in drilling processes, as well as methods for making and using such drill rods and systems. A drill rod configured for sonic drilling operations can include a cylindrical body having an interior surface and an exterior surface. A first connector may be located on a first end of the cylindrical body and a second connector may be located on a second end of the cylindrical body. The first connector and the second connector can be complementary. The drill rod can include a helical feature and a corresponding helical channel on the exterior surface of the cylindrical body. The helical feature and corresponding helical channel can be configured for moving material displaced during a drilling operation in an axial direction away from one end of the drill rod to the other.

Abstract: Implementations of the present invention relate generally to methods, systems, and apparatus for absorbing vibration and shock impulses created during drilling operations. In particular, implementations of the present invention include drill-string shock absorbers adapted to absorb longitudinal forces produced during a drilling operation. For example, drill-string shock absorbers in accordance with at least one implementation of the present invention include a generally cylindrical housing having a first end and a second end coupled together by a radially interlocking joint. Such a configuration can reduce mechanical failure and increase the operating life of the shock absorber by transmitting torsional forces directly between the ends of the housing and reducing stresses from being transferred to fastening means securing the first and second ends of the cylindrical housing together.

Abstract: An electric power generator includes a conduit disposed in a wellbore penetrating subsurface formations and at least one piezoelectric transducer in contact with the conduit. The piezoelectric transducer is configured to undergo stress in response to vibration in the conduit. The transducer includes a plurality of piezoelectric crystals stacked in a thickness direction and each polarized in the thickness direction. The transducer comprises at least one of a composite rubber layer disposed between successive piezoelectric crystals, and at least one support at a longitudinal end of the transducer configured to cause the crystals to bend in response to vibration in the conduit.

Abstract: A down hole vibration dampener is disclosed that uses a set of polyurethane rings and steel support rings to create a shock absorber within the drill string to reduce the amount of vibration in the drill string. A splined mandrel extends longitudinally within a hollow cylindrical housing. A seal structure present between the exterior of the mandrel and the interior of the housing forms a lubricant receiving chamber. The series of polyurethane and steel rings are located in the lubricant chamber and are compressible longitudinally to absorb vibration and shock loads.

Abstract: Vibrational apparatus capable of providing a vibrational output. The apparatus includes an assembly having a shuttle capable of shuttling between complementary structures, at least one of which complementary structures provides the vibrational output. The arrangement includes a drive to rotate the shuttle and there are magnetic interactions between the rotating shuttle and the complementary structures such that interactions with each complementary structure, and the phasing of the complementary structures relative to the shuttle, and alternating magnetic results forces in the shuttling movement of the shuttle.

Abstract: An active vibration control device improves drilling by actively applying a dampening profile and/or a controlled vibration to a drill string and/or bottomhole assembly (BHA). Embodiments of the present invention control the behavior of a drill string and/or BHA in order to prevent or minimize the occurrence of harmful drill string/BHA motion and/or to apply a vibration to the drill string/BHA that improves one or more aspects of the drilling process. Measurements of one or more selected parameters of interest are processed to determine whether the undesirable vibration or motion is present in the drill string or BHA and/or whether the drill string and/or BHA operation can be improved by the application of a controlled vibration. If either or both conditions are detected, corrective action is formulated and appropriate control signals are transmitted to one or more devices in the drill string and/or BHA.

Abstract: The present invention relates to a method for drilling a hole and installing a geothermal transfer apparatus. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a hollow drill string into the ground, the hollow drill string having an inner space. The hole is drilled to a desired depth by rotating and vibrating the hollow drill string into the ground while discharging fluid into the inner space of the hollow drill string. A geothermal transfer apparatus is lowered into the inner space of the hollow drill string following the drilling of the hole to the desired depth. The drill string is then removed from the ground.

Abstract: An active vibration control device improves drilling by actively applying a dampening profile and/or a controlled vibration to a drill string and/or bottomhole assembly (BHA). Embodiments of the present invention control the behavior of a drill string and/or BHA in order to prevent or minimize the occurrence of harmful drill string/BHA motion and/or to apply a vibration to the drill string/BHA that improves one or more aspects of the drilling process. Measurements of one or more selected parameters of interest are processed to determine whether the undesirable vibration or motion is present in the drill string or BHA and/or whether the drill string and/or BHA operation can be improved by the application of a controlled vibration. If either or both conditions are detected, corrective action is formulated and appropriate control signals are transmitted to one or more devices in the drill string and/or BHA.

Abstract: A device and system for improving efficiency of subterranean cutting elements uses a controlled oscillation super imposed on steady drill bit rotation to maintain a selected rock fracture level. In one aspect, a selected oscillation is applied to the cutting element so that at least some of the stress energy stored in an earthen formation is maintained after fracture of the rock is initiated. Thus, this maintained stress energy can thereafter be used for further crack propagation. In one embodiment, an oscillation device positioned adjacent to the drill bit provides the oscillation. A control unit can be used to operate the oscillation device at a selected oscillation. In one arrangement, the control unit performs a frequency sweep to determine an oscillation that optimizes the cutting action of the drill bit and configures the oscillation device accordingly. One or more sensors connected to the control unit measure parameters used in this determination.

Abstract: A vibrating downhole tool comprising a housing, an inner mandrel disposed within the housing and configured to receive a drilling fluid, a mass coupled to the inner mandrel, and a plurality of turbine blades configured to receive the drilling fluid and to rotate the inner mandrel and the mass, thereby causing the vibrating downhole tool to vibrate.

Abstract: A percussion drill, and methods of using the same, including a shank in mechanical alignment with a piston-hammer and a valve in fluid communication with the piston-hammer. The percussion drill further includes an internal hydraulic dampening system for reducing the velocity of the piston-hammer when the shank is forward of a power position relative to the velocity of the piston-hammer when the shank is in a power position. Preferably, the internal hydraulic dampening system includes mechanical alignment of a portion of the piston-hammer with a port in fluid communication with the valve, operable to reduce fluid flow into an area surrounding the valve when the piston-hammer is forward of its position relative to its normal operation.

Abstract: An underground drilling method where drilling fluid pulsing down hole tool is combined with a multiple in series pistons down hole tool to provide vigorous vibrations in the drill string and deliver vibrating energy to the drill bit to increase penetration rates and reduce friction between the drill string and the hole. One example method and apparatus shown can operate a simple percussive down hole mud hammer.

Abstract: The present invention relates to a method for drilling a hole and installing a geothermal transfer apparatus. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a hollow drill string into the ground, the hollow drill string having an inner space. The hole is drilled to a desired depth by rotating and vibrating the hollow drill string into the ground while discharging fluid into the inner space of the hollow drill string. A geothermal transfer apparatus is lowered into the inner space of the hollow drill string following the drilling of the hole to the desired depth. The drill string is then removed from the ground.

Abstract: In one aspect of the present invention, a drilling assembly has a string of downhole tools connected to a drill bit with a bit body intermediate a shank and a working face. The drill bit is connected to the string of tools at the shank. A continuous fluid passageway is formed within the bit body and the string of tools. A valve mechanism disposed within the fluid passageway is adapted to substantially cyclically build-up and release pressure within the fluid passageway such that a pressure build-up results in radial expansion of at least a portion of the fluid passageway and wherein a pressure release results in a contraction of the portion of the fluid passageway. The expansion and contraction of the portion of the fluid passageway varies a weight loaded to the drill bit.

Abstract: A vibrating downhole tool comprising a housing, an inner mandrel disposed within the housing and configured to receive a drilling fluid, a mass coupled to the inner mandrel, and a plurality of turbine blades configured to receive the drilling fluid and to rotate the inner mandrel and the mass, thereby causing the vibrating downhole tool to vibrate.

Abstract: In one aspect of the invention, a method for drilling a bore hole includes the steps of deploying a drill bit attached to a drill string in a well bore, the drill bit having an axial jack element with a distal end protruding beyond a working face of the drill bit; engaging the distal end of the jack element against the formation such that the formation applies a reaction force on the jack element while the drill string rotates; and applying a force on the jack element that opposes the reaction force such that the jack element vibrates and imposes a resonant frequency into the formation.

Abstract: There is provided a method for drilling a cased hole and installing a micropile. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a drill string into the ground. A retrievable drill bit is operatively connected to the drill string. The cased hole is drilled to a desired depth by rotating and vibrating the drill string into the ground. The retrievable drill bit is retrieved from the cased hole following the drilling of the cased hole to the desired depth. A micropile is lowered into the cased hole following the retrieval of the retrievable drill bit. Grouting material may be discharged into the cased hole before or after the drill string is removed from the ground. In another embodiment, a removable drill bit may be used in place of the retrievable drill bit.

Abstract: There is provided a method for drilling a cased hole and installing a geothermal transfer apparatus. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a drill string into the ground. A retrievable drill bit is operatively connected to the drill string. The cased hole is drilled to a desired depth by rotating and vibrating the drill string into the ground. The retrievable drill bit is retrieved from the cased hole following the drilling of the cased hole to the desired depth. A geothermal transfer apparatus is lowered into the cased hole following the retrieval of the retrievable drill bit. Grouting material may be discharged into the cased hole before or after the drill string is removed from the ground.

Abstract: Implementations of the present invention relate generally to methods, systems, and apparatus for absorbing vibration and shock impulses created during drilling operations. In particular, implementations of the present invention include drill-string shock absorbers adapted to absorb longitudinal forces produced during a drilling operation. For example, drill-string shock absorbers in accordance with at least one implementation of the present invention include a generally cylindrical housing having a first end and a second end coupled together by a radially interlocking joint. Such a configuration can reduce mechanical failure and increase the operating life of the shock absorber by transmitting torsional forces directly between the ends of the housing and reducing stresses from being transferred to fastening means securing the first and second ends of the cylindrical housing together.

Abstract: According to the invention, a system for drilling a cavity in a medium is disclosed. The system may include a bottom hole assembly. The bottom hole assembly may include a first longitudinal segment and at least one drill bit. The first longitudinal segment may include a first length of chassis having a first cross section. The first cross section may be configured such that the first longitudinal segment may have a greater stiffness in a first lateral direction than in a lateral direction different than the first lateral direction.

Abstract: The present invention relates to a method for drilling a hole and installing a geothermal transfer apparatus. A sonic drilling apparatus is positioned at a desired location. The sonic drilling apparatus includes a rotating and vibrating apparatus for rotating and vibrating a hollow drill string into the ground, the hollow drill string having an inner space. The hole is drilled to a desired depth by rotating and vibrating the hollow drill string into the ground while discharging fluid into the inner space of the hollow drill string. A geothermal transfer apparatus is lowered into the inner space of the hollow drill string following the drilling of the hole to the desired depth. The drill string is then removed from the ground.

Abstract: A clamping device connects two, axially harmonically oscillating components which oscillate, as a result of their respective plane surfaces impacting each other with a frequency ? in the form of a stationary longitudinal wave with a distance A between two nodes K. The clamping device includes an axially extending springy gripping yoke having two clamping elements. The two clamping elements are located at opposite ends of the gripping yoke. The two clamping elements are spaced apart from each other by a distance corresponding to the distance A between the two nodes K of the longitudinal wave.

Abstract: An electric power generator includes a conduit disposed in a wellbore penetrating subsurface formations and at least one piezoelectric transducer in contact with the conduit. The piezoelectric transducer is configured to undergo stress in response to vibration in the conduit. The transducer includes a plurality of piezoelectric crystals stacked in a thickness direction and each polarized in the thickness direction. The transducer comprises at least one of a composite rubber layer disposed between successive piezoelectric crystals, and at least one support at a longitudinal end of the transducer configured to cause the crystals to bend in response to vibration in the conduit.

Abstract: The present invention relates to a control device for an impulse-generating device for inducing a shock wave in a tool, in which said impulse-generating device comprises an impact element for transmitting said shock wave to said tool, a counter pressure chamber acting against the impact element and a device for reducing a pressure in the counter-pressure chamber. The control device comprises control means for regulating the reduction of the pressure in said computer-pressure chamber. The invention also relates to an impulse-generating device.

Abstract: Disclosed are hydrocarbon recovery drill string apparatus, subterranean hydrocarbon recovery drilling methods, and subterranean hydrocarbon recovery methods. In one embodiment, a hydrocarbon recovery drill string apparatus includes an elongated assembly within which a rotatable drill rod is received. The assembly comprises a longitudinal axis, a drill rod entrance end, and a drill rod exit end. The assembly comprises a tailcuttings diverter pipe proximate the drill rod exit end, with the tailcuttings diverter pipe defining an initial fluid flow path of the tailcuttings from the longitudinal axis which is acute from the longitudinal axis. Other apparatus and method aspects are contemplated.

Abstract: In one aspect of the present invention, a method has steps for forming a wellbore with a tool string bit having a body intermediate a shank and a working face. The bit body has a fluid passageway and at least a portion of a jack element is disposed within the body. The jack element also has an end forming at least a portion of a relief mechanism in the fluid passageway and a distal end substantially protruding from the working face. The bit connected to a tool string is deployed into a wellbore. Fluid is passed through the fluid passageway. A bottom of the wellbore is destructed by pulsing the fluid traveling through the passageway by opening and closing the relief mechanism.

Abstract: A drive system for driving and/or extracting an elongate member. The drive system comprises a piston drive assembly, a hydraulic system, and a vibration drive assembly. The piston drive assembly comprises a piston member, and the piston member engages the elongate member. The hydraulic system is operatively connected to the piston drive assembly to apply a drive force to the piston member. The vibration drive assembly generates a vibratory force. The vibration drive assembly is operatively connected to the piston drive assembly. The drive system operates in a first mode in which the drive force and the vibratory force are applied to the piston member along a drive axis.

Abstract: The invention relates to a damping device for an output shaft (26) in a gearbox (14,16), where the gearbox (14,16) is arranged for rotation of a rotational degree of freedom (Z4,Z5) in a rock-drilling rig (2), and thus for positioning of the same, and where the damping device (18) comprises a brake (38) that acts on the output shaft (26) of the gearbox (14,16), which brake (38) acts as an oscillation damper for the movement of the output shaft (26), whereby a gearbox (14,16) with play can be used for applications that require a high degree of precision such as positioning, e.g. measuring a position for a drill hole. The invention also relates to a gearbox (14,16) and a rock-drilling rig (2) with damping device (18), respectively.

Abstract: In one aspect of the invention, a downhole tool string component comprises a fluid passageway formed between a first and second end. A valve mechanism is disposed within the fluid passageway adapted to substantially cyclically build-up and release pressure within the fluid passageway such that a pressure build-up results in radial expansion of at least a portion of the fluid passageway and wherein a pressure release results in a contraction of the portion of the fluid passageway. The valve mechanism disposed within the fluid passageway comprises a spring. Expansion and contraction of the portion of the fluid passageway varies a weight loaded to a drill bit disposed at a drilling end of the drill string.

Abstract: In one aspect of the present invention, a drilling assembly has a string of downhole tools connected to a drill bit with a bit body intermediate a shank and a working face. The drill bit is connected to the string of tools at the shank. A continuous fluid passageway is formed within the bit body and the string of tools. A valve mechanism disposed within the fluid passageway is adapted to substantially cyclically build-up and release pressure within the fluid passageway such that a pressure build-up results in radial expansion of at least a portion of the fluid passageway and wherein a pressure release results in a contraction of the portion of the fluid passageway. The expansion and contraction of the portion of the fluid passageway varies a weight loaded to the drill bit.

Abstract: Vibrational apparatus capable of providing a vibrational output, said apparatus comprising or including an assembly having a shuttle capable of shuttling between complementary structures, at least one of which complementary structures provides the vibrational output, the arrangement being characterised in that there is a drive to rotate the shuttle and there are magnetic interactions between the rotating shuttle and the complementary structures such that interactions with each complementary structure, and the phasing of the complementary structures relative to the shuttle, alternating magnetic results in the shuttling movement of the shuttle.

Abstract: Apparatus and methods for drilling with casing. In an embodiment, methods and apparatus for deflecting casing using a diverter apparatus are disclosed. In another embodiment, the apparatus comprises a motor operating system disposed in a motor system housing, a shaft operatively connected to the motor operating system, the shaft having a passageway, and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft. In another aspect, methods and apparatus for directionally drilling a casing into the formation are disclosed. Methods and apparatus for measuring the trajectory of a wellbore while directionally drilling a casing into the formation are also described.

Abstract: Apparatus and methods are described for highly attenuating vibrations of a drillstring assembly while drilling. In one embodiment, vibrations are attenuated by introducing one or more vibration attenuation modules at appropriate assembly locations. For example, vibration attenuation modules may be inserted at locations where vibration energy is expected to be maximal. In one embodiment the vibration attenuation modules include cavities loosely packed with particles of solid material such as sand or metallic powder. In one embodiment, the cavity walls are rough and/or include geometric features that enhance vibration energy transfer to the loosely packed particles in the cavity(ies). The vibration energy is dissipated via friction and inelastic particle-particle and particle-wall collisions that occur as a result of drillstring motion.

Abstract: Methods and apparatus for mitigating the effects of vibration of various tools, such as those used downhole, by utilizing a vibration isolation device that incorporates Shape Memory Alloys (SMAs). For instance, in some embodiments, a vibration isolation device may be designed and deployed in a manner such that, when a vibration isolation device is operated in an expected manner, the force on the SMAs from static loading is sufficient to induce partial phase transformation between the austenite and martensite phases. This partial phase transformation may result in a reduced stiffness of the vibration isolation device in comparison to a tool in either a full austenite phase or full martensite phase.

Abstract: The present invention provides a chemometric equation to estimate fluid density, viscosity, dielectric constant and resistivity for a formation fluid sample downhole. The chemometric estimates can be used directly as estimated values for fluid density, viscosity, dielectric constant and resistivity for a formation fluid sample downhole. The chemometric estimates can also be plugged into a Levenberg-Marquardt (LM) non-linear least squares fit, as an initial estimate of the parameter to be estimated by the LM fit. If the initial parameter estimate is too far from the actual parameter values, the LM algorithm may take a long time to converge or even fail to converge entirely. The present invention estimates an initial value of a parameter that provides a high probability that the LM algorithm will converge to a global minimum.

Abstract: According to one aspect of the invention there is provided a rotary-vibratory drilling apparatus. The drilling assembly is comprised of a vibratory apparatus, a rotary drive apparatus, a drill string, a first conduit and a second conduit. The first conduit communicates with the second conduit and the second conduit communicates with the drill string. The drilling assembly may further include a fluid reservoir communicating with the first conduit. Fluid may be discharged from the fluid reservoir into the first conduit, fluid may be discharged from the first conduit into the second conduit, and fluid may be discharged from the second conduit into the drill string. The first conduit may be threadedly connected to the second conduit.

Abstract: An active vibration control device improves drilling by actively applying a dampening profile and/or a controlled vibration to a drill string and/or bottomhole assembly (BHA). Embodiments of the present invention control the behavior of a drill string and/or BHA in order to prevent or minimize the occurrence of harmful drill string/BHA motion and/or to apply a vibration to the drill string/BHA that improves one or more aspects of the drilling process. Measurements of one or more selected parameters of interest are processed to determine whether the undesirable vibration or motion is present in the drill string or BHA and/or whether the drill string and/or BHA operation can be improved by the application of a controlled vibration. If either or both conditions are detected, corrective action is formulated and appropriate control signals are transmitted to one or more devices in the drill string and/or BHA.

Abstract: A method for installing a heat exchange pipe loop in a borehole, the method, in at least certain aspects, including drilling a borehole with a sonic drill system having a head and casing connected thereto, a drill apparatus on a lower end of the casing movable by the sonic drill head to drill the borehole, pumping fluid into the casing and up to earth surface in an annular space in the borehole so that drilled material flows to the earth surface, lowering a heat exchange pipe loop down into the casing, introducing grout into the casing around the heat exchange pipe loop, and extracting the casing from the borehole.

Abstract: A back-off tool for use in a tubular member disposed inside a wellbore. The back-off tool includes a housing and at least one sonic wave generator mounted within the housing. The sonic wave generator is configured to generate a plurality of sonic waves.

Abstract: An apparatus for imparting mechanical vibration on a down-hole drilling system including a body, first and second couplers and a rotating member. The body includes ports configured to pass fluid through the body, and the first and second couplers are configured to couple the body to the down-hole drilling system. The rotating member is located at least partially in the body and is rotatable about an axis of rotation in response to flow of the fluid such that rotation of the rotating member generates mechanical vibration imparted on the down-hole drilling system.