Patent ID: 9016400
Filing Date: 2015-04-28
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, and one or more fluid channels radially-spaced from the central channel; one or more radially extendable pistons housed in the steering section; wherein the central channel extends axially from the first end and is configured to flow drilling fluid through the steering section; wherein each of the fluid channels extends to one of the pistons and is configured to flow drilling fluid to the corresponding piston; and a fluid-metering assembly configured to selectively meter the flow of drilling fluid into one or more of the fluid channels 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 second component includes a central through bore and one or more fluid inlets disposed about the central through bore, wherein the central through bore of the second component is in fluid communication with the central channel of the steering section; wherein each fluid inlet of the second component is in fluid communication with at least one 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 into one or more of the fluid inlets of the second component; wherein the first component comprises a flange and a sleeve extending axially from the flange; wherein the sleeve extends into the central through bore of the second component and slidingly engages the lower component.