Abstract: In a method for sealing and controlling fluid pressure in an annular fluid passageway in a wellbore related process, use is made of an annular fluid passageway sealing device, which includes a chamber delimited by chamber end members each provided with an opening therein so that the drilling tubulars string passes through said chamber and said chamber end members. The lower chamber end member is exposed, at least partially, to wellbore related fluid pressure in the annular fluid passageway. The housing is provided with an inlet and an outlet in communication with said chamber. Use is made of a pump that circulates a high viscosity liquid. The inlet and the outlet are vertically offset from each other and the chamber is provided with one or more narrow annular gap defining members that are arranged between vertically spaced apart feed and discharge zones.

Abstract: A directional casing drilling system includes a casing string, a drilling rig and a retrievable Bottom Hole Assembly (BHA). The drilling rig includes a casing drive for rotating the casing string in the borehole, a control system for controlling the casing drive, and a mud pump for pumping a continuous flow of drilling mud into the casing string. The BHA includes a torque transfer section, with which it is secured in the casing string, and a drill bit section held in a drilling position in the torque transfer section. It further includes a mud drive that rotates the drilling position of the drill bit section about the longitudinal axis of the torque transfer section, and a communicating device for communicating the orientation of the drill bit to the control system. The BHA is steered by adjusting the rotational speed of the casing string.

Abstract: In a method for sealing and controlling fluid pressure in an annular fluid passageway in a wellbore related process, use is made of an annular fluid passageway sealing device, which includes a chamber delimited by chamber end members each provided with an opening therein so that the drilling tubulars string passes through said chamber and said chamber end members. The lower chamber end member is exposed, at least partially, to wellbore related fluid pressure in the annular fluid passageway. The housing is provided with an inlet and an outlet in communication with said chamber. Use is made of a pump that circulates a high viscosity liquid. The inlet and the outlet are vertically offset from each other and the chamber is provided with one or more narrow annular gap defining members that are arranged between vertically spaced apart feed and discharge zones.

Abstract: A directional casing drilling system includes a casing string, a drilling rig and a retrievable Bottom Hole Assembly (BHA). The drilling rig includes a casing drive for rotating the casing string in the borehole, a control system for controlling the casing drive, and a mud pump for pumping a continuous flow of drilling mud into the casing string. The BHA includes a torque transfer section, with which it is secured in the casing string, and a drill bit section held in a drilling position in the torque transfer section. It further includes a mud drive that rotates the drilling position of the drill bit section about the longitudinal axis of the torque transfer section, and a communicating device for communicating the orientation of the drill bit to the control system. The BHA is steered by adjusting the rotational speed of the casing string.

Abstract: A device for anchoring in a casing in a borehole in the ground. The device comprises a shaft oriented in an axial direction, the shaft having a torque transfer section. The torque transfer section has axially oriented outer cam surfaces extending radially outwardly in a rotational sense. The shaft further has a plurality of clamping bodies circumferentially distributed around the torque transfer section with a limited movability relative to the torque transfer section in rotational sense and in radial directions. The clamping bodies each have an inner, axially oriented clamping body surface facing one of the cam surfaces of the torque transfer section and an outer surface defining a segment of a cylinder coaxial with said shaft.

Abstract: A device for anchoring in a casing in a borehole in the ground. The device comprises a shaft oriented in an axial direction, the shaft having a torque transfer section. The torque transfer section has axially oriented outer cam surfaces extending radially outwardly in a rotational sense. The shaft further has a plurality of clamping bodies circumferentially distributed around the torque transfer section with a limited movability relative to the torque transfer section in rotational sense and in radial directions. The clamping bodies each have an inner, axially oriented clamping body surface facing one of the cam surfaces of the torque transfer section and an outer surface defining a segment of a cylinder coaxial with said shaft.