Abstract: The disclosure relates to a thread formation and to a downhole tool comprising a hollow tubular pipe section having an end on which the thread formation is provided. The thread formation comprises a first thread having a first thread start and a second thread having a second thread start, wherein the first thread start is operatively rotationally in advance of the second thread start. Accordingly, the first thread is configured to engage at least partially with a complementary thread formation on another downhole tool before the second thread engages with the complementary thread formation.

Abstract: A drill rod for assembly with other drill rods to form a drillstring used for fluid reverse circulation drilling comprising: an outer drill rod comprising a lightweight drill rod used in core drilling with a bore, an inner drill rod comprising a bore, a first coupling member removably coupled to one end of the inner drill rod, a second coupling member removably coupled to a second end of the inner drill rod, wherein the first and second coupling members centre the inner drill rod within the outer drill rod.

Abstract: In one aspect the present invention may be said to comprise a drill rod for assembly with other drill rods to form a drillstring used for fluid reverse circulation drilling comprising: an outer drill rod comprising a bore that is tapered at each end, an inner drill rod within the outer drill rod, and a retention member removably coupled to each end of the inner drill rod to retain the inner drill rod between the tapered ends of the outer drill rod.

Abstract: The present invention relates to a wireline retrieval head assembly and downhole tool, the wireline retrieval head assembly for coupling to the downhole tool for installation in and retrieval from downhole in a mineral industry field of use, wherein a first of the wireline retrieval head assembly and downhole tool has a retention member that has or is configured to receive a pivot member and a second of the wireline retrieval head assembly and downhole tool has a complementary link with an opening for receiving the pivot member, such that the link can be coupled to the retention member to create a pivot coupling to allow for articulation between the wireline retrieval head assembly and the downhole tool during installation and retrieval of the downhole tool, and the link can be removed from the retention member to remove the downhole tool from the wireline retrieval head assembly.

Abstract: The disclosure relates to a thread formation and to a downhole tool comprising a hollow tubular pipe section having an end on which the thread formation is provided. The thread formation comprises a first thread having a first thread start and a second thread having a second thread start, wherein the first thread start is operatively rotationally in advance of the second thread start. Accordingly, the first thread is configured to engage at least partially with a complementary thread formation on another downhole tool before the second thread engages with the complementary thread formation.

Abstract: In one aspect the present invention comprises a wireline retrievable coring apparatus for incorporation into a drillstring, comprising: a housing for coupling to a drill string housing, a drill bit, a turbine comprising a stator coupled to the housing and a rotor within the stator, the rotor coupled to rotate the drill bit, a core barrel through the turbine and in communication with the drill bit for capturing a core, a fluid path to the drill bit via the turbine to rotate the turbine, wherein the core barrel is rotationally isolated from the rotor and is fluidly isolated from the fluid path.

Abstract: A drill bit for coupling in use downhole drilling apparatus, the drill bit comprising: an annular coring drill bit that is rotatable to cut a formation bore face to create a core plug, a concentric drill bit that can be repeatedly axially moved (such as by oscillation (such as a vibration) and/or impact) to break the core plug.

Abstract: The present invention relates to a wireline retrieval head assembly and downhole tool, the wireline retrieval head assembly for coupling to the downhole tool for installation in and retrieval from downhole in a mineral industry field of use, wherein a first of the wireline retrieval head assembly and downhole tool has a retention member that has or is configured to receive a pivot member and a second of the wireline retrieval head assembly and downhole tool has a complementary link with an opening for receiving the pivot member, such that the link can be coupled to the retention member to create a pivot coupling to allow for articulation between the wireline retrieval head assembly and the downhole tool during installation and retrieval of the downhole tool, and the link can be removed from the retention member to remove the downhole tool from the wireline retrieval head assembly.

Abstract: A drill bit for coupling in use downhole drilling apparatus, the drill bit comprising: an annular coring drill bit that is rotatable to cut a formation bore face to create a core plug, a concentric drill bit that can be repeatedly axially moved (such as by oscillation (such as a vibration) and/or impact) to break the core plug.

Abstract: In one aspect the present invention comprises a wireline retrievable coring apparatus for incorporation into a drillstring, comprising: a housing for coupling to a drill string housing, a drill bit, a turbine comprising a stator coupled to the housing and a rotor within the stator, the rotor coupled to rotate the drill bit, a core barrel through the turbine and in communication with the drill bit for capturing a core, a fluid path to the drill bit via the turbine to rotate the turbine, wherein the core barrel is rotationally isolated from the rotor and is fluidly isolated from the fluid path.

Abstract: Disclosed is a mechanical force generator for use in a drillstring that provides a sinusoidal or near sinusoidal oscillating output, comprising: a rotatable cam plate connected to a mass, the cam plate having two opposed oblique bearing surfaces rotatable through a bearing, wherein upon rotation, the two opposed oblique bearing surfaces cam against the bearing to oscillate the mass longitudinally, wherein the bearing comprises opposing bearings for bearing against the opposed oblique bearing surfaces and wherein at least one bearing adjusts to follow the respective opposed bearing surface and maintain engagement.

Abstract: Disclosed is a mechanical force generator for use in a drillstring that provides a sinusoidal or near sinusoidal oscillating output, comprising: a rotatable cam plate connected to a mass, the cam plate having two opposed oblique bearing surfaces rotatable through a bearing, wherein upon rotation, the two opposed oblique bearing surfaces cam against the bearing to oscillate the mass longitudinally, wherein the bearing comprises opposing bearings for bearing against the opposed oblique bearing surfaces and wherein at least one bearing adjusts to follow the respective opposed bearing surface and maintain engagement.

Abstract: An excitation apparatus suitable for use downhole having interengaged masses at least in part confined or guided so as to be movable as an interengaged assembly on an axis, one mass (“rotatable mass”) being rotatable relative to the other mass about the axis to cyclically vary the axial length of the assembly of the interengaged masses, a rotary drive, and an interposed spring (of any kind) between the rotary drive and the rotatable mass able to transmit torque from the rotary drive to the rotatable mass yet vary in its extent responsive to the interengaged masses.

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 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: An excitation apparatus suitable for use downhole having interengaged masses at least in part confined or guided so as to be movable as an interengaged assembly on an axis, one mass (“rotatable mass”) being rotatable relative to the other mass about the axis to cyclically vary the axial length of the assembly of the interengaged masses, a rotary drive, and an interposed spring (of any kind) between the rotary drive and the rotatable mass able to transmit torque from the rotary drive to the rotatable mass yet vary in its extent responsive to the interengaged masses.