07823655 is referenced by 36 patents and cites 52 patents.

Methods and apparatus for using a quill to steer a hydraulic motor when elongating a wellbore in a direction having a horizontal component, wherein the quill and the hydraulic motor are coupled to opposing ends of a drill string, by monitoring an actual toolface orientation of a tool driven by the hydraulic motor via monitoring a drilling operation parameter indicative of a difference between the actual toolface orientation and a desired toolface orientation, and then adjusting a position of the quill by an amount that is dependent upon the monitored drilling operation parameter.

Title
Directional drilling control
Application Number
11/859378
Publication Number
7823655 (B2)
Application Date
September 21, 2007
Publication Date
November 2, 2010
Inventor
Chris Papouras
Houston
TX, US
John Thomas Scarborough
Houston
TX, US
Beat Kuttel
Spring
TX, US
Brian Ellis
Spring
TX, US
Scott Boone
Houston
TX, US
Agent
Haynes and Boone
Assignee
Canrig Drilling Technology
TX, US
IPC
E21B 44/02
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