Patent · US Expired

Method and apparatus for drilling curved boreholes

US7373995B2 · kind B2 · utility

19Cited by
3References
13Claims
0Family size

Inventors

Key dates

Filing dateNov 28, 2005
Grant dateMay 20, 2008
Priority date
Expiry dateMar 18, 2026

Classification

  • Technology area (CPC E)Fixed Constructions
  • CPC primaryE21B7/062
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

The invention is an improved rotary steerable tool. The improved rotary steerable tool comprises a control tube that slides vertical within a mandrel in response to changes in drilling fluid pressure, thereby opening and closing a channel between the mandrel and a piston chamber in a rotationally isolated sleeve. With the channel open, a piston in the piston chamber is exposed to the drilling fluid. When the drilling pressure is sufficient to cause the piston to move, the piston forces a deflection pad outward. After the deflection pad engages a borehole wall, any additional increases in pressure force the opposing side of sleeve toward the opposite wall, thereby tilting the direction of any attached drill bit. An optional guide lug and alignment sleeve orient the deflection pad with respect to other components.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.