Drilling apparatus with motor-driven pump steering control

US6439325B1 · kind B1 · utility

Assignee

• Baker Hughes Holdings LLC · US

Inventors

• Volker Peters · Celle, DE
• Detlef Ragnitz · Detmold, DE

Key dates

• Filing date: Jul 19, 2000
• Grant date: Aug 27, 2002
• Expiry date: Jul 19, 2020

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21B7/068
• WIPO field: Civil engineering
• WIPO sector: Other fields

Abstract

The present invention provides apparatus for power transfer over a nonconductive gap between rotating and non-rotating members of downhole oilfield tools. The gap may contain a non-conductive fluid, such as drilling fluid or oil for operating hydraulic devices in the downhole tool. The downhole tool, in one embodiment, is a drilling assembly wherein a drive shaft is rotated by a downhole motor to rotate the drill bit attached to the bottom end of the drive shaft. A substantially non-rotating sleeve around the drive shaft includes a plurality of independently operated force application members used to exert the force required to maintain and/or alter the drilling direction. In the preferred system, one or more mechanically operated devices such as hydraulic units control the force application members. A transfer device transfers electrical power between the rotating and non-rotating members, and the electric power is converted directly to mechanical power. An electronic control circuit or unit associated with the rotating member controls the transfer of power between the rotating member and the non-rotating member.