Boring and drilling apparatus

A boring apparatus comprising:

• a rotatable drive shaft;
• a boring member comprising a tubular member;
• a mechanism for converting rotational motion of the drive shaft into longitudinal reciprocal motion of the boring member;
• and
• a rotational boring device provided ahead of the boring member, the rotational boring device being driven, in use, by the drive shaft;
• wherein a leading end of the tubular member tapers from a main body portion of the tubular member to a peripherally extending leading edge thereof;
• wherein the boring member further comprises a body mounted on the drive shaft;
• and
• wherein the body is rigidly connected to the tubular member by one or more radially extending members.

A boring apparatus comprising:

• a rotatable drive shaft;
• a boring member comprising a tubular member;
• a mechanism for converting rotational motion of the drive shaft into longitudinal reciprocal motion of the boring member;
• and
• a rotational boring device provided ahead of the boring member, the rotational boring device being driven, in use, by the drive shaft;
• wherein a leading end of the tubular member tapers from a main body portion of the tubular member to a peripherally extending leading edge thereof;
• wherein the boring member further comprises a body mounted on the drive shaft;
• and
• wherein the body and tubular member are arranged to engage or remain engaged on rotation of the body in a first direction, and disengage on rotation of the body in a second direction.

A boring apparatus comprising:

• a rotatable drive shaft;
• a boring member comprising a tubular member;
• a mechanism for converting rotational motion of the drive shaft into longitudinal reciprocal motion of the boring member;
• and
• a rotational boring device provided ahead of the boring member, the rotational boring device being driven, in use, by the drive shaft;
• wherein the mechanism for converting rotational motion of the drive shaft to longitudinal motion of the boring member comprises at least one cam track arrangement on one of the drive shaft and boring member, and at least one corresponding cam follower member on the other of the drive shaft and the boring member.

A boring apparatus comprising:

• a rotatable drive shaft;
• a boring member comprising a tubular member;
• a mechanism for converting rotational motion of the drive shaft into longitudinal reciprocal motion of the boring member;
• and
• a rotational boring device provided ahead of the boring member, the rotational boring device being driven, in use, by the drive shaft;
• wherein the rotational boring device is adjustable to a position in which the radius of the rotational boring device is less than the radius of the boring member.

An apparatus for boring, the apparatus comprising:

• a rotatable drive shaft;
• a drive mechanism for rotating the drive shaft;
• a first drilling member comprising an annular shroud, the first drilling member being mounted on the drive shaft by a mounting arrangement, the mounting arrangement comprising a mechanism for converting at least some of the rotary motion of the drive shaft into reciprocal motion of the first drilling member;
• a second drilling member arranged to extend beyond the first drilling member, the second drilling member being rotatably drivable by the drive shaft;
• and
• a fluid circulation arrangement for supplying fluid to the first drilling member and removing fluid therefrom.

A drill string assembly comprising:

• a rotatable drive shaft;
• a drive device for rotating the drive shaft;
• a tubular shroud;
• and
• a mounting device for selectively mounting the tubular shroud to the drive shaft, wherein the mounting device converts at least some rotary motion of the drive shaft to reciprocal motion of the tubular shroud;
• a drilling member in the form of a drill head extending beyond and before the tubular shroud, the drilling member being rotatably drivable by the drive shaft;
• and
• a fluid circulation arrangement for supplying fluid to the tubular shroud and removing fluid therefrom.

A drill string assembly comprising:

• a rotatable drive shaft;
• a drive device for rotating the drive shaft;
• a tubular shroud;
• and
• a mounting device for selectively mounting the tubular shroud to the drive shaft, wherein the mounting device converts at least some rotary motion of the drive shaft to reciprocal motion of the tubular shroud;
• and
• a drilling member in the form of a drill head extending beyond and before the tubular shroud;
• wherein the drill head is selectively movable between a first position of substantially the same radius as the tubular shroud, and a second position of lesser radius than the tubular shroud.

A drill string assembly comprising:

• a rotatable drive shaft;
• a drive device for rotating the drive shaft;
• a tubular shroud;
• and
• a mounting device for selectively mounting the tubular shroud to the drive shaft, wherein the mounting device converts at least some rotary motion of the drive shaft to reciprocal motion of the tubular shroud;
• a drilling member in the form of a drill head extending beyond and before the tubular Shroud;
• and
• one or more casing sections;
• wherein the casing sections include precast concrete or similar coatings.

A drill string assembly comprising:

• a rotatable drive shaft;
• a drive device for rotating the drive shaft;
• a tubular shroud;
• and
• a mounting device for selectively mounting the tubular shroud to the drive shaft, wherein the mounting device converts at least some rotary motion of the drive shaft to reciprocal motion of the tubular shroud;
• a drilling member in the form of a drill head extending beyond and before the tubular Shroud;
• and
• one or more casing sections;
• further comprising intumescent coatings on selected portions of the casing sections.

A method of drilling and casing a wellbore, the method comprising the steps of:

• running a drill string assembly into a bore, the assembly comprising a rotatable drive shaft, a drive device for rotating the drive shaft, a tubular shroud, a mounting device for selectively mounting the tubular shroud to the drive shaft and for convening at least some of the rotary motion of the drive shaft to reciprocal motion of the tubular shroud, and a drilling member in the form of a drill head extending beyond and before the tubular shroud;
• running at least one casing section into the bore on the drill string assembly;
• unmounting the tubular shroud from the drive shaft;
• and
• removing the drilling member and the drive shaft from the bore, to leave the tubular shroud and the casing sections in the bore.

A boring apparatus comprising:

• a rotatable drive shaft;
• a boring member;
• and
• a mechanism for convening rotational motion of the drive shaft into longitudinal reciprocal motion of the boring member;
• wherein the mechanism for convening rotational motion of the drive shaft into longitudinal reciprocal motion of the boring member comprises at least one cam track arrangement on one of the drive shaft and the boring member, and at least one corresponding cam follower member on the other of the drive shaft and the boring member;
• wherein the at least one cam track arrangement is substantially sinusoidal in shape.

An apparatus for boring, the apparatus comprising:

• a rotatable drive shaft;
• a drive mechanism for rotating the drive shaft;
• a drilling member mounted on the drive shaft by a mounting arrangement, the mounting arrangement comprising a mechanism for converting at least some rotary motion of the drive shaft into reciprocal motion of the drilling member;
• and
• a fluid circulation arrangement for supplying fluid to the drilling member and removing fluid therefrom;
• wherein the fluid circulation arrangement comprises a fluid delivery conduit extending to the drilling member, and a fluid removal conduit extending from the drilling member, wherein the fluid delivery conduit comprises one or more fluid delivery ports for permitting escape of fluid from the fluid delivery conduit to environment of the drilling member, the fluid delivery ports being directed rearwardly with respect to a direction of fluid delivery flow.

A drill string assembly comprising:

• a rotatable drive shaft;
• a drive device for rotating the drive shaft;
• a tubular shroud;
• a mounting device for selectively mounting the tubular shroud to the drive shaft;
• one or more casing sections comprising intumescent coatings on selected portions thereof, the intumescent coatings being selected to intumesce at a selected predetermined temperature;
• and
• a heating device for heating the intumescent coatings, the heating device comprising heating elements embedded in the intumescent coatings, and operable from surface.

A drill string assembly comprising:

• a rotatable drive shaft;
• a drive device for rotating the drive shaft;
• a tubular shroud;
• a mounting device for selectively mounting the tubular shroud to the drive shaft;
• and
• one or more casing sections comprising intumescent coatings on selected portions thereof, the intumescent coatings being provided adjacent joints configured to be disposed between successive casing sections.