Abstract: A drilling fluid delivery system for drilling boreholes with a drill bit, includes a primary flow circuit having a relatively high flow rate for transferring drilling fluid to and from the drill bit. The system also includes a secondary flow circuit having a relatively low flow rate for transferring drilling fluid to and from the primary flow circuit. Furthermore, the system includes a cuttings transfer system, such as a hydrocyclone or a rotating filter, between the primary and secondary flow circuits. When the cutting transfer system is in use, it receives fluid containing cuttings from the primary circuit and separates the fluid into a first stream that contains substantially no cuttings and a second stream containing cuttings. The first stream is returned to the primary flow circuit and the second stream is directed to the secondary flow circuit.

Abstract: A rotary drill bit is provided comprising a bit body, which includes a connecting portion for connection to a conveyance and a drilling portion. The drilling portion includes a plurality of cutting elements each having at least one cutting surface, the drilling portion being operable in at least two different drilling orientations, and the drilling surface being rotatable in one of two opposing directions, being a first direction and an opposing second direction.

Abstract: A drilling system for drilling a borehole in an underground formation, comprises a rotary drill bit, a drilling drive mechanism that is capable of applying both rotating the drill bit and applying an axial force to the drill bit, and a control system that is capable of controlling the drive mechanism so as to control rotation of the drill bit and the axial force applied to the drill bit in order to control the depth of cut created by the drill bit when drilling through the formation. A method of drilling a borehole in an underground formation with a rotary drill bit, comprises applying rotation and an axial force to the drill bit and controlling the rotation and axial force so as to control the depth of cut created by the drill bit when drilling through the formation.

Abstract: A system and method are provided for drilling a wellbore. The wellbore is formed with a drilling tool that cuts through a formation. A pumping system removes cuttings from the drilling tool and also transports the cuttings along at least a portion of the wellbore formed behind the drilling tool.

Abstract: A rotary drill bit is provided comprising a bit body, which includes a connecting portion for connection to a conveyance and a drilling portion. The drilling portion includes a plurality of cutting elements each having at least one cutting surface, the drilling portion being operable in at least two different drilling orientations, and the drilling surface being rotatable in one of two opposing directions, being a first direction and an opposing second direction.

Abstract: A drilling fluid delivery system for use in drilling boreholes with a drill bit, the system comprising: a primary flow circuit having a relatively high flow rate for transferring drilling fluid to and from the drill bit; a secondary flow circuit having a relatively low flow rate for transferring drilling fluid to and from the primary flow circuit; and a cuttings transfer system, such as a hydrocyclone or a rotating filter, between the primary and secondary flow circuits which, in use, receives fluid containing cuttings from the primary circuit, separates the fluid into a first stream that contains substantially no cuttings and a second stream containing cuttings, the first stream being returned to the primary flow circuit and the second stream being directed to the secondary flow circuit.

Abstract: A system and method are provided for drilling a wellbore. The wellbore is formed with a drilling tool that cuts through a formation. A pumping system removes cuttings from the drilling tool and also transports the cuttings along at least a portion of the wellbore formed behind the drilling tool.

Abstract: A drilling system for drilling a borehole in an underground formation, comprises a rotary drill bit, a drilling drive mechanism that is capable of applying both rotating the drill bit and applying an axial force to the drill bit, and a control system that is capable of controlling the drive mechanism so as to control rotation of the drill bit and the axial force applied to the drill bit in order to control the depth of cut created by the drill bit when drilling through the formation. A method of drilling a borehole in an underground formation with a rotary drill bit, comprises applying rotation and an axial force to the drill bit and controlling the rotation and axial force so as to control the depth of cut created by the drill bit when drilling through the formation.