Steering system for drill string
AssigneeSchlumberger Technology Corporation
InventorGuy James Rushton
Life of this patent
Estimating the term…
Abstract
A technique facilitates directional drilling of boreholes. A steerable system has a plurality of actuator pistons slidably mounted in a mechanical structure. The mechanical structure comprises a radially inward portion containing ports to deliver a portion of drilling mud to the plurality of actuator pistons. The mechanical structure also has a radially outward portion positioned to define a main flow passage extending longitudinally through the steerable system between the radially inward portion and the radially outward portion of the mechanical structure.
Claims20
A system for forming a directional borehole, comprising:
- a rotary steerable system having a plurality of actuator pistons slidably mounted in a mechanical structure, the mechanical structure comprising:
- a radially inward portion containing ports to deliver actuating mud to the plurality of actuator pistons;
- a radially outward portion;
- and
- a piston chamber portion extending radially between the radially inward portion and the radially outward portion, the piston chamber portion having piston passages for receiving the plurality of actuator pistons, the mechanical structure defining a main flow passage extending longitudinally through the rotary steerable system between the radially inward portion and the radially outward portion for directing a flow of actuating mud to a drill bit, the piston passages extending radially inward of the main flow passage and into the radially inward portion in a radial plane perpendicular to a centerline of the mechanical structure intersecting the piston passages and the main flow passage.
A method, comprising:
- providing a rotary steerable system with a mechanical structure having a main flow passage for delivering drilling mud to a drill bit, the main flow passage being located radially outward of a radially inward portion of the mechanical structure;
- positioning the rotary steerable system in a drill string;
- routing drilling mud through the drill string including through the main flow passage;
- using the drilling mud to operate actuator pistons of the rotary steerable system via valve controlled ports located at a radially inward position relative to the main flow passage and within the radially inward portion of the mechanical structure;
- and
- directing a remainder of the drilling mud past the rotary steerable system via the main flow passage, wherein in a radial plane perpendicular to a centerline of the mechanical structure intersecting the main flow passage and the valve controlled ports, the valve controlled ports are located radially inward of the main flow passage.
A system for steering during drilling, comprising:
- a drill string having a rotary steerable system, the drill string being constructed to enable a flow of drilling mud therethrough, the rotary steerable system comprising:
- a plurality of actuator pistons operated within corresponding piston passages by the flow of drilling mud;
- a plurality of ports located at a radially inward position within the rotary steerable system, the ports of the plurality of ports being positioned to direct flow of the drilling mud to corresponding actuator pistons of the plurality of actuator pistons;
- and
- a mechanical structure having, in a radial plane perpendicular to a centerline of the rotary steerable system, a main flow passage located radially outward of the plurality of ports and radially outward of radially inward portions of the corresponding piston passages, the main flow passage directing a remainder of the drilling mud past the rotary steerable system.
Dependencies are inferred from the claim text.