Abstract: A system and method are provided for using controlled vibrations to bias a drilling direction of a bottom hole assembly (BHA) in a borehole. In one example, the system includes a movement mechanism and a vibration control mechanism. The movement mechanism is configured to use mechanical energy provided by a mechanical energy source to enable translational movement of a first surface relative to a second surface to allow the first surface to repeatedly impact the second surface to produce a plurality of vibration beats. The vibration control mechanism is configured to influence a drilling direction in which the BHA is drilling by controlling an amplitude of the vibration beats to regulate an impact force between the first surface and the second surface, where the amplitude is controlled based on directional information corresponding to the BHA.

Abstract: A drilling apparatus including a drill bit and a nutation device. The drilling apparatus is configured to enable the drill bit to be rotated at a rotation frequency while the nutation device simultaneously nutates the drill bit at a nutation frequency. The nutation device may include a vibrating device for imposing vibrations upon the drilling apparatus at a vibration frequency, thereby causing nutation of the drill bit at the nutation frequency. The drilling apparatus may include a tuning mechanism for tuning the vibration frequency of the vibrating device. A method including rotating a drill bit at a rotation frequency and simultaneously nutating the drill bit at a nutation frequency.

Abstract: Method to estimate severity of downhole vibration for a wellbore drill tool assembly, comprising: identifying a dataset comprising selected drill tool assembly parameters; selecting a reference downhole vibration index for the drill tool assembly; identifying a surface parameter and calculating a reference surface vibration attribute for the selected reference downhole vibration index; determining a surface vibration attribute derived from at least one surface measurement or observation obtained in a drilling operation, the determined surface vibration attribute corresponding to the identified surface parameter; and estimating a downhole vibration index by evaluating the determined surface vibration attribute with respect to the identified reference surface vibration attribute.

Abstract: A device in place as, or suitable for use as, a vibrational tool of or in a downhole assembly, the device having a first magnetic assembly which is to be, or can be, rotated relative to a second magnetic assembly and which, when so rotated, causes the second magnetic assembly to oscillate and/or reciprocate at least substantially in an axial manner; wherein the oscillating and/or reciprocating magnetic assembly, at least substantially, at either one end, or both ends, is attached to and constrained in its oscillations and/or reciprocation by a compliant member thereby allowing the output force to be distributed to the outer body of the vibrational tool and/or any attached uphole and/or downhole tooling, from the compression and extension of the compliant member in a substantially sinusoidal manner.

Abstract: A method includes oscillating, with a first acceleration profile, at least a portion of a drill string using a top drive at least indirectly coupled to the drill string and includes oscillating, with a second acceleration profile different from the first acceleration profile, at least a portion of the drill string using the top drive. The method also includes oscillating, with a third acceleration profile, at least a portion of the drill string using the top drive, wherein the third acceleration profile is optimized based on feedback associated with the oscillation with the first acceleration profile and feedback associated with the oscillation with the second acceleration profile.

Abstract: An apparatus for reducing vibration includes: a damping assembly configured to be fixedly attached to a downhole component, the downhole component configured to rotate within a borehole in an earth formation, the damping assembly having a damping frequency that is tuned relative to a selected natural vibration frequency of the rotating downhole component to reduce vibration due to component rotation.

Abstract: A vibration system for drill bit housing and method is disclosed, which may be utilized to assist in lowering a drill string into a wellbore through which drilling fluid is pumped. In one embodiment, a drill bit housing contains a symmetrical rotatable member positioned to rotate in response to drilling fluid pumped through the housing, whereby a mechanical interconnection connected to the rotatable member produces vibrations within the drill bit housing for advancing bottom hole assemblies.

Abstract: A drill bit direction system and method is disclosed that modifies or biases the stochastic movement of the drill bit to change a drilling direction of a drilling system. The direction of the drill bit is monitored to determine if the direction happens to align in some way with a preferred direction. If the direction isn't close enough to a preferred or desired direction, stochastic motion of the drill bit in the borehole may be controlled and/or motion of the drill bit under a side force acting on the drill bit to direct the drilling may be focused or biased to modify the direction of drilling closer to the preferred direction. Any of a number of stochastic motion control mechanisms or biasing mechanisms can be used. Some embodiments can resort to conventional steering mechanisms to supplement the stochastic motion control or side force biasing mechanisms.

Abstract: Disclosed is a method for estimating downhole lateral vibrations a drill tubular disposed in a borehole penetrating the earth or a component coupled to the drill tubular. The method includes rotating the drill tubular to drill the first borehole and performing a plurality of measurements in a time window of one or more parameters of the drill tubular at or above a surface of the earth during the rotating using a sensor. The method further includes estimating the downhole lateral vibrations using a processor that receives the plurality of measurements.

Abstract: A rotary drill and a double-layer drilling rod mechanism are disclosed. The rotary drill comprises a vibration excitation mechanism (1), a rotating mechanism (3) and a flushing mechanism (10). The rotating mechanism (3) consists of a rotary box (8), a driving gear (7), a rotary gear (6) and a rotary connecting sleeve (9). The rotary gear (6) is tightly cased on the rotary connecting sleeve (9) and engaged with the driving gear (7). A connecting rod (2) is provided in the rotary connecting sleeve (9), and the rotary connecting sleeve (9) is connected with the double-layer drilling rod mechanism (11). An impact drilling string (25) located by a guide bearing bush (26) is arranged in the outer rotary drilling pipe (28) of the double-layer drilling rod mechanism (11); a latch (24) for connecting the connecting rod (2) is arranged at the top of the inner impact drilling string (25); and an impact head (12) connected with the impact drilling string (25) is arranged in the drilling bit connecting sleeve (29).

Abstract: A system and method are provided for producing controlled vibrations within a borehole. In one example, the system includes an encoder plate having a first surface, an anvil plate having a second surface, a movement mechanism configured to enable translational movement of the encoder plate relative to the anvil plate to allow the first surface to repeatedly impact the second surface to produce a plurality of vibration beats, and a vibration control mechanism configured to selectively control an amplitude of the vibration beats to encode information therein.

Abstract: The invention relates to a drive device for driving a drill rod, which has an outer rod and an inner rod, with a first rotary drive unit, with which the outer rod can be driven in a rotating manner via an outer drive shaft, a second rotary drive unit, with which the inner rod can be driven in a rotating manner independently of the outer rod via an inner drive shaft, and a vibration unit for generating a vibration, which has a vibration element that can be driven in a vibrating manner. For transmission of the vibration to the outer drive shaft the vibration element is connected via a first transmission unit to the outer drive shaft and for transmission of the vibration to the inner drive shaft the vibration element is connected via a second transmission unit to the inner drive shaft.

Abstract: A drilling method comprises controlling operation of a drill string to maintain at least a portion of the drill string in forward whirl.

Abstract: A tubular downhole tool string component having a sidewall with a fluid passageway formed therein between a first end and second end, and a valve mechanism 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 sidewall and wherein a pressure release results in a radial contraction of the portion of the sidewall. The valve mechanism disposed within the fluid passageway comprises a spring. Radial expansion and contraction of the portion of the sidewall varies a weight loaded to a drill bit disposed at a drilling end of the drill string.

Abstract: A pressure pulse generating method and apparatus for use with a drill string includes a top and bottom subs for attaching the apparatus within the drill string; a rotor/stator; a drive assembly; and a nozzle sub which includes a nozzle assembly comprising a nozzle holder and a replaceable nozzle; and a nozzle housing having pulse openings. The nozzle holder has fluid ports which periodically align with the pulse openings as the nozzle holder rotates within the nozzle housing to achieve a desired pulse amplitude, frequency and waveform.

Abstract: An apparatus for use in a horizontal section of a drill string is disclosed. The apparatus includes a motor that is connected to the horizontal section of the drill string. The motor is adapted to impart vibrations in the horizontal section of the drill string, where the vibrations are at about the lateral resonant frequency of the horizontal section of the drill string.

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: A method, apparatus and computer-readable medium for reducing a vibration of a drill string in a borehole. A sensor of the drill string obtains one or more measurements of a parameter of the vibration. A processor determines at least one force for controlling the measured vibration from the measured parameter. At least one actuator applies the determined at least one force against the borehole wall to control the vibration of the drill string.

Abstract: The present invention relates to a method and a device for controlling at least one drill parameter when drilling in rock with a drilling machine. During drilling, an impulse-generating device uses an impact means to induce shock waves in a tool working against the rock, a pressure level for a shock-wave-generating pressure is controlled during the drilling, and said drilling machine includes a damping chamber that can be pressurized. The contact of the drilling machine against the rock is affected at least partially by the pressure prevailing in said damping chamber. When the pressure in said damping chamber exceeds said first level and is below said second level, the percussion pressure is controlled as a function of the pressure in said damping chamber.

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: A mobile drill rig has a drill mast, a carriage mounted to the drill mast for vertical movement, and a vibratory drill head having a sine generator and a rotation mechanism for imparting vibration and rotation to a drill rod string. An elastomeric torsion coupler couples the rotation mechanism to the sine generator to transmit rotational force to the drill rod string while isolating vibrations of the sine generator from the rotation mechanism. Another coupler connects the drill head to the carriage in a manner that allows floating vertical movement of the drill head relative to the carriage while isolating vibrations of the sine generator from the carriage. Elastomeric bumpers limit the vertical movement of the drill head relative to the carriage. Elastomeric spacers located between the rotation mechanism and the sine generator handle the vertical loading and maintain the proper spacing between the sine generator and the rotation mechanism.

Abstract: A vibratory unit interposed between a planetary drive and earth-penetrating device, e.g., an auger, is powered by the hydraulic system of a tractor, skid loader or the like. The unit includes a housing having a base plate with a slidable striker plate mounted therein. A Kelly bar displaces the planetary drive from the auger and through the housing. A rotatable shaft with weights eccentrically mounted thereon produces vibratory forces and urges the striker plate into contact with the base plate to provide hammer-like forces on the auger.

Abstract: A sonic drill head comprising an outer housing, an isolation system, a sine generator and a spindle. The sine generator generates a linear sinusoidal vibration force through the rotation of a plurality of eccentric masses. The sine generator is configured to translate the linear sinusoidal force to the spindle in a direction corresponding to the spindle's axis of rotation. The sine generator supports the spindle within the housing such that the spindle is free to rotate about the spindle axis. The spindle is generally a hollow tube section thereby allowing the passage of drilling fluid, mud, cuttings, and/or tooling. The isolation system generally reduces the transfer of the vibration force generated by the sine generator to the outer housing, yet is able to transfer an applied thrust force from the outer housing to the sine generator.

Abstract: A downhole tool assembly has a component that is sensitive to shock and vibration. A reciprocating element is coupled to the component. The reciprocating element has an axial internal passage and an outer surface. A housing has an internal axial bore for receiving the reciprocating element for axial reciprocal motion therein. A retainer is mounted to the housing and seals the housing between the component and the reciprocating element. A first spring is located between the housing and the reciprocating element. A second spring is located between the reciprocating element and the retainer. A first reciprocating seal is located between the reciprocating element and the housing. A second reciprocating seal is located between the connector and the retainer. A fluid is contained by the reciprocating seals inside the housing. The reciprocating element permits a limited amount of fluid to flow between sides thereof.

Abstract: A method for controlling a resonance enhanced rotary drill comprising a rotary drill bit and an oscillator for applying axial oscillatory loading to the rotary drill bit, the method comprising: controlling frequency (f) of the oscillator in the resonance enhanced rotary drill whereby the frequency (f) is maintained in the range (D2 Us/(8000 ?Am))1/2?f?Sf(D2 Us/(8000 ?Am))1/2 where D is diameter of the rotary drill bit, Us is compressive strength of material being drilled, A is amplitude of vibration, m is vibrating mass, and Sf is a scaling factor greater than 1; and controlling dynamic force (Fd) of the oscillator in the resonance enhanced rotary drill whereby the dynamic force (Fd) is maintained in the range [(?/4)D2effUs]?Fd?SFd[(?/4)D2effUs] where Deff is an effective diameter of the rotary drill bit, Us is a compressive strength of material being drilled, and SFd is a scaling factor greater than 1, wherein the frequency (f) and the dynamic force (Fd) of the oscillator are controll

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: A pile adapted to be driven into the ground and having retaining formations to retain one or more geothermal conduit loops. Each conduit loop is formed by opposed longitudinal conduit sections interconnected at a lower end by an interconnecting section. The conduit loops are adapted for flow of a heat exchange fluid therein. The retaining formations retain the one or more conduit loops in close proximity to the pile through the attachment means as the pile is driven into the ground.

Abstract: In some example embodiments, a system includes a drill string having a drill bit. The drill string extends through at least part of a well bore. The system also includes a first vibrational sensor, positioned on the drill bit to measure, at a first location on the drill string, an amplitude of one or more of an axial vibration and a lateral vibration. The system also includes a second vibrational sensor, positioned above the drill bit and on the drill string. The second vibration sensor is to measure, at a second location on the drill string, one or more of an axial vibration and a lateral vibration. The system includes a processor unit to determine a type of vibration based on a comparison of the amplitude at the first location to the amplitude at the second location, wherein the type of vibration is at least one of bit whirl of the drill bit and a while of a bottom hole assembly that is part of the drill string.

Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: Disclosed is an apparatus for vibrating a downhole drill string operable to have a drilling fluid pumped therethrough. The apparatus comprises a tubular body securable to the drill string and having a central bore therethrough, a valve in the tubular body for venting the drilling fluid out of the drill string and a valve actuator for cyclically opening and closing the valve. The method comprises pumping a drilling fluid down the drill string and cyclically venting the drilling fluid through the valve so as to cyclically reduce the pressure of the drilling fluid in the drill string. The valve can comprise a tubular body port and a corresponding rotor port selectably alignable with the tubular body port as the rotor rotates within the central bore. The valve actuator can comprise at least one vane on the rotor for rotating the rotor as the drilling fluid flows therepast.

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 vibrating downhole tool includes a housing having a central axis defined therethrough, an inner mandrel disposed within the housing and configured to receive a drilling fluid, wherein the inner mandrel is misaligned relative to the housing central axis, and a plurality of turbine blades configured to receive the drilling fluid and to rotate the inner mandrel, thereby causing the downhole tool to vibrate.

Abstract: A downhole flow pulsing device comprises a housing connected in series with a drill string and a valve with a rotating portion in the housing arranged to vary an area of a flow passage through the housing. A fluid actuated positive displacement motor drives rotation of the valve. A drive link permits the rotating portion of the valve to be optionally coupled directly to the motor of the drill string. The valve includes radially oriented rotating ports intermittently communicating with surrounding fixed ports and a bypass channel. Axial displacement of the rotating ports relative to the fixed ports and bypass channel permits amplitude of the downstream fluid pulses to be adjusted. The valve includes a number of circumferentially spaced ports which differs from a prescribed number of pressure fluctuations in the fluid for each full rotation of the rotor of the drill motor.

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: Disclosed is an apparatus for vibrating a downhole drill string operable to have a drilling fluid pumped therethrough. The apparatus comprises a tubular body securable to the drill string and having a central bore therethrough, a valve in the tubular body for venting the drilling fluid out of the drill string and a valve actuator for cyclically opening and closing the valve. The method comprises pumping a drilling fluid down the drill string and cyclically venting the drilling fluid through the valve so as to cyclically reduce the pressure of the drilling fluid in the drill string. The valve may comprise a tubular body port and a corresponding rotor port selectably alignable with the tubular body port as the rotor rotates within the central bore. The valve actuator may comprise at least one vane on the rotor for rotating the rotor as the drilling fluid flows therepast.

Abstract: Disclosed is 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. The cased 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 micropile is then lowered into the cased hole. Grouting material may be discharged into the cased hole before or after the drill string is removed from the ground.

Abstract: There is provided a method for drilling a hole into the ground and installing a geothermal transfer loop. A drilling apparatus is positioned at a desired location. The drilling apparatus includes a rotating and vibrating apparatus, such as a sonic drill, for rotating and vibrating a hollow drill string into the ground. The hollow drill string having an inner space. A 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. The fluid forming a fluid column in the inner space of the drill string. The fluid column impedes entry of ground materials into the inner space of the drill string and is vibrated to create a water hammer for adding an additional drilling force. A geothermal transfer loop is lowered into the inner space of the hollow drill string and the drill string is removed from the ground. The method may also include discharging grouting material into the hole.

Abstract: A method of conducting borehole operations using a system including an elongate tubular conveyance that is moved through the borehole, the method comprising imposing a torsional vibration at a predetermined frequency on the tubular conveyance as it is moved through the borehole: wherein the predetermined frequency is obtained by determining the frequency-dependent mobility of the system based on the relationship between rotational velocity and torque for the system; and imposing torsional vibrations at a frequency where the relationship is optimised.

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: A vibratory unit interposed between a planetary drive and earth-penetrating device, e.g., an auger, is powered by the hydraulic system of a tractor, skid loader or the like. The unit includes a housing having a base plate with a slidable striker plate mounted therein. A Kelly bar displaces the planetary drive from the auger and through the housing. A rotatable shaft with weights eccentrically mounted thereon produces vibratory forces and urges the striker plate into contact with the base plate to provide hammer-like forces on the auger.

Abstract: The invention relates to a method and a device for controlling drilling parameters when drilling into rock with a drilling machine. During drilling, an impulse-generating device using an impact means is arranged to induce shock waves in a tool held against the rock, the said impulse-generating device being displaceable in the drilling direction relative to a supporting means, wherein a pressure level of a shock-wave-generating pressure is controlled during the drilling operation. A drilling speed of the said drilling is determined by determining a movement of the impulse-generating device with respect to the said supporting means, and the said shock-wave-generating pressure is controlled as a function of the said drilling speed that has been determined.

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 tool used for cutting coke or other hard materials in drums, adapted for being mounted to a boring rod with which the water can be run under pressure into the tool thus that, the water can be run toward the boring and cutting nozzles, being provided with a valve mechanism that can rotate about a coupling angle for releasing and closing the flow channel ports depending on a control input, with a first coupling position of the valve mechanism for boring and another coupling position for cutting, whereby the valve mechanism can be coupled at a water pressure reduced to the coupling pressure by rotating about the coupling angle, is simplified as to construction and handling in that the valve mechanism comprises a valve body in the water intake area of the casing, which has a cylindrical shape and a section for the water flowing inside the casing, as well as being rotationally mounted and having the possibility to be lifted and lowered in a cylindrical section of the inner wall of the casing, the valve body bein

Abstract: A drill bit direction system and method is disclosed that modifies or biases the stochastic movement of the drill bit and/or stochastic interactions between the drill bit and an inner-wall of a borehole being drilled by a drilling system to change the direction of drilling of the drilling system. The direction of the drill bit is monitored to determine if the direction happens to align in some way with a preferred direction. If the direction isn't close enough to a preferred direction, a biasing mechanism modifies the stochastic movement in an attempt to modify the direction closer to the preferred direction. Any of a number of biasing mechanisms can be used. Some embodiments can resort to conventional steering mechanisms to supplement the biasing mechanism.

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: 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: An arrangement and a method for controlling at least one drill parameter when drilling in rock with a rock drill, comprising an impulse-generating device arranged to induce shock waves in a tool acting against the rock with a percussive force generated via a shock wave-generating pressure. The arrangement also comprises a rotation-generating device arranged to supply a torque to the impact device with a rotation generated via a rotation pressure, and a pressurisable damping chamber arranged to at least partially regulate the rock drill's contact with the rock via the prevailing pressure in the damping chamber, in which connection the shock wave-generating pressure is regulated depending on the rotation pressure.

Abstract: A downhole assembly for insertion into a borehole comprising an articulated mandrel, a passive and an active damping mechanism operating on said mandrel for exercising control over torsional stick-slip and further proposing an improvement over the prior art which diminishes lateral shock.

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 system and method for controlling an oscillatory penetration apparatus. An embodiment is a system and method for controlling a sonic drill having a displacement and an operating range and operating at a phase difference, said sonic drill comprising a push-pull piston and eccentrics, said method comprising: operating the push-pull piston at an initial push-pull force while the eccentrics are operated at a plurality of different operating frequencies within the operating range of the sonic drill and measuring the displacement at each operating frequency; determining an efficient operating frequency for the material being drilled and operating the eccentrics at said efficient operating frequency; determining the phase difference at which the sonic drill is operating; and if the phase difference is not substantially equal to minus ninety degrees, operating the push-pull piston at another push-pull force.