Abstract: A steering tool for extended-reach directional drilling in three dimensions comprises a mud pulse telemetry section, a rotary section, and a flex section assembled as an integrated system in series along the length of the tool. The flex section comprises a flexible drive shaft and a deflection actuator for applying hydraulic pressure along the length of the shaft for bending the shaft when making inclination angle adjustments during steering. The rotary section comprises a rotator housing coupled to the deflection housing for rotating the deflection housing for making azimuth angle adjustments during steering. The onboard mud pulse telemetry section receives inclination and azimuth angle steering commands together with actual inclination and azimuth angle feedback signals during steering for use in controlling operation of the flex section and rotary section for steering the tool along a desired course.

Abstract: A long reach rotary drilling assembly comprises an elongated conduit extending through a bore in an underground formation, a drill bit for being rotated to drill the bore, a 3-D steering tool on the conduit for steering the drill bit, and a tractor on the conduit for applying force to the drill bit. The steering tool includes a telemetry section, a rotary section, and a flex section assembled as an integrated system in series along the length of the tool. The flex section comprises a flexible drive shaft to which a bending force is applied when making inclination angle adjustments. The rotary section includes a deflection housing which rotates for making azimuth angle adjustments. The telemetry section receives inclination and azimuth angle steering commands together with actual inclination and azimuth angle feedback signals for controlling operation of the flex section and rotary section to steer the drilling assembly along a desired course.

Abstract: A tractor for moving within a borehole comprises an elongated tractor body and two propulsion assemblies that are longitudinally movably engaged with the body. The tractor body has annular pistons configured to receive hydraulic thrust to propel the body longitudinally. Each propulsion assembly includes a gripper and one or more propulsion cylinders. The gripper has an actuated position in which the gripper limits relative movement between the gripper and the inner surface of the borehole, and a retracted position in which the gripper permits substantially free relative movement between the gripper and the inner surface of the borehole. Each propulsion cylinder contains one of the pistons. The tractor includes a control assembly having a plurality of valves and hydraulic circuitry which control the sequencing of fluid distribution to the propulsion cylinders, and of the actuation and retraction of the grippers. A throttle valve controls the fluid flowrate to the pistons.

Abstract: A downhole drilling tractor for moving within a borehole comprises a tractor body, two packerfeet, two aft propulsion cylinders, and two forward propulsion cylinders. The body comprises aft and forward shafts and a central control assembly. The packerfeet and propulsion cylinders are slidably engaged with the tractor body. Drilling fluid can be delivered to the packerfeet to cause the packerfeet to grip onto the borehole wall. Drilling fluid can be delivered to the propulsion cylinders to selectively provide downhole or uphole hydraulic thrust to the tractor body. The tractor receives drilling fluid from a drill string extending to the surface. A system of spool valves in the control assembly controls the distribution of drilling fluid to the packerfeet and cylinders. The valve positions are controlled by motors. A programmable electronic logic component on the tractor receives control signals from the surface and feedback signals from various sensors on the tool.

Abstract: A downhole drilling tractor for moving within a borehole comprises a tractor body, two packerfeet, two aft propulsion cylinders, and two forward propulsion cylinders. The body comprises aft and forward shafts and a central control assembly. The packerfeet and propulsion cylinders are slidably engaged with the tractor body. Drilling fluid can be delivered to the packerfeet to cause the packerfeet to grip onto the borehole wall. Drilling fluid can be delivered to the propulsion cylinders to selectively provide downhole or uphole hydraulic thrust to the tractor body. The tractor receives drilling fluid from a drill string extending to the surface. A system of spool valves in the control assembly controls the distribution of drilling fluid to the packerfeet and cylinders. The valve positions are controlled by motors. A programmable electronic logic component on the tractor receives control signals from the surface and feedback signals from various sensors on the tool.

Abstract: A tractor for moving within a borehole comprises an elongated tractor body and two propulsion assemblies that are longitudinally movably engaged with the body. The tractor body has annular pistons configured to receive hydraulic thrust to propel the body longitudinally. Each propulsion assembly includes a gripper and one or more propulsion cylinders. The gripper has an actuated position in which the gripper limits relative movement between the gripper and the inner surface of the borehole, and a retracted position in which the gripper permits substantially free relative movement between the gripper and the inner surface of the borehole. Each propulsion cylinder contains one of the pistons. The tractor includes a control assembly having a plurality of valves and hydraulic circuitry which control the sequencing of fluid distribution to the propulsion cylinders, and of the actuation and retraction of the grippers. A throttle valve controls the fluid flowrate to the pistons.

Abstract: A method and apparatus for propelling a tool having a body within a passage. The tool includes a gripper including at least a gripper portion which can assume a first position that engages an inner surface of the passage and limits relative movement of the gripper portion relative to the inner surface. The gripper portion can also assume a second position that permits substantially free relative movement between the gripper portion and the inner surface of the passage. The tool includes a propulsion assembly for selectively continuously moving the body of the tool with respect to the gripper portion while the gripper portion is in the first position. This allows the tool to move different types of equipment within the passage. For example, the tool advantageously may be used in drilling processes to provide continuous force to a drill bit. This enables the drilling of extended horizontal boreholes.

Abstract: A tractor for moving within a borehole comprises an elongated tractor body and two propulsion assemblies that are longitudinally movably engaged with the body. The tractor body has annular pistons configured to receive hydraulic thrust to propel the body longitudinally. Each propulsion assembly includes a gripper and one or more propulsion cylinders. The gripper has an actuated position in which the gripper limits relative movement between the gripper and the inner surface of the borehole, and a retracted position in which the gripper permits substantially free relative movement between the gripper and the inner surface of the borehole. Each propulsion cylinder contains one of the pistons. The tractor includes a control assembly having a plurality of valves and hydraulic circuitry which control the sequencing of fluid distribution to the propulsion cylinders, and of the actuation and retraction of the grippers. A throttle valve controls the fluid flowrate to the pistons.

Abstract: A method and apparatus for propelling a tool having a body within a passage. The tool includes a gripper including at least a gripper portion which can assume a first position that engages an inner surface of the passage and limits relative movement of the gripper portion relative to the inner surface. The gripper portion can also assume a second position that permits substantially free relative movement between the gripper portion and the inner surface of the passage. The tool includes a propulsion assembly for selectively continuously moving the body of the tool with respect to the gripper portion while the gripper portion is in the first position. This allows the tool to move different types of equipment within the passage. For example, the tool advantageously may be used in drilling processes to provide continuous force to a drill bit. This enables the drilling of extended horizontal boreholes.

Abstract: A method and apparatus for propelling a tool having a body within a passage. The tool includes a gripper including at least a gripper portion which can assume a first position that engages an inner surface of the passage and limits relative movement of the gripper portion relative to the inner surface. The gripper portion can also assume a second position that permits substantially free relative movement between the gripper portion and the inner surface of the passage. The tool includes a propulsion assembly for selectively continuously moving the body of the tool with respect to the gripper portion while the gripper portion is in the first position. This allows the tool to move different types of equipment within the passage. For example, the tool advantageously may be used in drilling processes to provide continuous force to a drill bit. This enables the drilling of extended horizontal boreholes.

Abstract: A jacking mechanism for jacking a well casing or other well pipe vertically, and including a hydraulic control system in which a reversible variable displacement pump acts in one condition to deliver pressure fluid in parallel with another pump to the lower end of a jacking cylinder to actuate the piston thereof upwardly, with fluid discharging from the upper end of the cylinder to the variable displacement pump and being metered therethrough to regulate the rate of upward movement of the piston. In a second condition of the apparatus, flow through the variable displacement pump is reversed to lower the piston, and a variable restriction valve regulates discharge of fluid from the lower end of the cylinder to act with the variable displacement pump in regulating downward movement of the piston and supported pipe.