Steerable rotary drilling systems
US6089332A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 1998 |
| Grant date | Jul 18, 2000 |
| Priority date | — |
| Expiry date | Jan 8, 2018 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/22
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A steerable rotary drilling system has a bottom hole assembly which includes, in addition to the drill bit, a modulated bias unit and a control unit, the bias unit comprising a number of hydraulic actuators around the periphery of the unit, each having a movable thrust member which is hydraulically displaceable outwardly for engagement with the formation of the borehole being drilled. Each actuator may be connected, through a control valve, to a source of drilling fluid under pressure and the operation of the valve is controlled by the control unit so as to modulate the fluid pressure supplied to the actuators as the bias unit rotates. If the control valve is operated in synchronism with rotation of the bias unit the thrust members impart a lateral bias to the bias unit, and hence to the drill bit, to control the direction of drilling. Pulses transmitted through the drilling fluid as a result of operation of the bias unit are detected and interpreted at the surface, or at a different location downhole, to obtain information regarding the operation of the bias unit or other parts of the bottom hole assembly. Data signals from downhole sensors may be arranged to modify the control an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.