Abstract: An earth removal member for drilling a wellbore with casing or liner includes a tubular body and a head. The head is fastened to or formed with an end of the body, has a face and a side, is made from a high strength material, and has a port formed through the face. The earth removal member further includes a blade. The blade is formed on the head, extends from the side and along the face, and is made from the high strength material. The earth removal member further includes cutters disposed along the blade; and a nozzle adapter. The nozzle adapter has a port formed therethrough, is longitudinally and rotationally coupled to the head, and is made from a drillable material. The earth removal member further includes a nozzle disposed in the adapter port and fastened to the nozzle adapter.

Abstract: In one embodiment, a casing bit drive assembly may be used with a casing drilling system. The casing bit drive assembly may include one or more of the following: a retrievable drilling motor; a decoupled casing sub; a releasable coupling between the motor and casing bit; a releasable coupling between the motor and casing; a cement diverter; and a casing bit.

Abstract: An earth removal member for drilling a wellbore with casing or liner includes a tubular body and a head. The head is fastened to or formed with an end of the body, has a face and a side, is made from a high strength material, and has a port formed through the face. The earth removal member further includes a blade. The blade is formed on the head, extends from the side and along the face, and is made from the high strength material. The earth removal member further includes cutters disposed along the blade; and a nozzle adapter. The nozzle adapter has a port formed therethrough, is longitudinally and rotationally coupled to the head, and is made from a drillable material. The earth removal member further includes a nozzle disposed in the adapter port and fastened to the nozzle adapter.

Abstract: A coupling device includes an upper adapter and a lower adapter. The lower adapter may be pre-installed on a downhole tool and positioned in a wellbore. The upper adapter may be attached to a conveyance and lowered into the wellbore for connection with the lower adapter. The upper adapter may be coupled to the lower adapter by sliding over the lower adapter and applying weight to actuate a locking mechanism. After coupling, axial and torque load may be transmitted from the conveyance to the downhole tool.

Abstract: An earth removal member for drilling a wellbore with casing or liner includes a tubular body and a head. The head is fastened to or formed with an end of the body, has a face and a side, is made from a high strength material, and has a port formed through the face. The earth removal member further includes a blade. The blade is formed on the head, extends from the side and along the face, and is made from the high strength material. The earth removal member further includes cutters disposed along the blade; and a nozzle adapter. The nozzle adapter has a port formed therethrough, is longitudinally and rotationally coupled to the head, and is made from a drillable material. The earth removal member further includes a nozzle disposed in the adapter port and fastened to the nozzle adapter.

Abstract: Embodiments of the present invention generally relate to an earth removal member with features for facilitating drill-through. In one embodiment, an earth removal member for drilling a wellbore with casing or liner includes a tubular body and a head. The head is fastened to or formed with an end of the body, has a face and a side, is made from a high strength material, and has a port formed through the face. The earth removal member further includes a blade. The blade is formed on the head, extends from the side and along the face, and is made from the high strength material. The earth removal member further includes cutters disposed along the blade; and a nozzle adapter. The nozzle adapter has a port formed therethrough, is longitudinally and rotationally coupled to the head, and is made from a drillable material. The earth removal member further includes a nozzle disposed in the adapter port and fastened to the nozzle adapter.

Abstract: Embodiments of the present invention generally relate to an earth removal member with features for facilitating drill-through. In one embodiment, an earth removal member for drilling a wellbore with casing or liner includes a tubular body and a head. The head is fastened to or formed with an end of the body, has a face and a side, is made from a high strength material, and has a port formed through the face. The earth removal member further includes a blade. The blade is formed on the head, extends from the side and along the face, and is made from the high strength material. The earth removal member further includes cutters disposed along the blade; and a nozzle adapter. The nozzle adapter has a port formed therethrough, is longitudinally and rotationally coupled to the head, and is made from a drillable material. The earth removal member further includes a nozzle disposed in the adapter port and fastened to the nozzle adapter.

Abstract: A method of forming a wellbore includes providing a drilling assembly comprising one or more lengths of casing and an axially retracting assembly having a first tubular; a second tubular at least partially disposed in the first tubular and axially fixed thereto; and a support member disposed in the second tubular and movable from a first axial position to a second axial position relative to the second tubular, wherein, in the first axial position, the support member maintains the second tubular axially fixed to the first tubular, and in the second axial position, allows the second tubular to move relative to the first tubular; and an earth removal member disposed below the axially retracting assembly. The method also includes rotating the earth removal member to form the wellbore; moving the support member to the second axial position; and reducing a length of the axially retracting assembly.

Abstract: A drilling tool having a pilot bit on an end of a main shaft is surrounded by outer shafts having mills on their ends. The bit and mills employ cutters with PDC. The pilot bit rotates in a direction opposite the direction of rotation of the mills. A transmission for rotating a main shaft, on which the pilot bit is mounted, and several secondary shafts, on which the mills are respectively mounted, is carried within a housing using diamond thrust and radial bearings. Power is applied to the main shaft and transmitted to the secondary shafts through diamond hardened gears. Drilling fluid is used to cool and lubricate the bearings and gears.