Patent ID: 8869916
Filing Date: 2014-10-28
Classification: E21B

Abstract:
1. A rotary steerable drilling apparatus comprising: a control assembly disposed within a cylindrical housing; a steering section having a central axis, a first end coupled to the housing, a second end, a central channel extending axially from the first end, and a fluid channel extending axially from the first end and radially-spaced from the central channel, wherein the central channel is configured to flow drilling fluid through the steering section to a cutting structure; a piston housed in the steering section, wherein the fluid channel in the steering section extends to the piston and is configured to flow drilling fluid to the piston, and wherein the piston is configured to move radially outward in response to drilling fluid supplied by the fluid channel; a fluid-metering assembly configured to selectively meter the flow of drilling fluid into the fluid channel of the steering section, wherein the fluid-metering assembly includes a first component coupled to the control assembly and a second component coupled to the steering section; wherein the first component includes a central through bore and a fluid port radially spaced from the central through bore; wherein the second component includes a central through bore and a fluid inlet radially-spaced from the central through bore of the second component, wherein the central through bore of the second component is in fluid communication with the central through bore of the first component and the central channel of the steering section, and wherein the fluid inlet of the second component is in fluid communication with the fluid channel of the steering section; wherein the control assembly is configured to move the first component relative to the second component to control the flow of drilling fluid through the fluid port into the fluid inlet of the second component; a filter module disposed in the housing and configured to filter the drilling fluid passing through the fluid port of the first component into the fluid inlet of the second component.