Apparatus and method for drilling and reaming a borehole
US6920944B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 26, 2002 |
| Grant date | Jul 26, 2005 |
| Priority date | — |
| Expiry date | May 5, 2023 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/322
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drilling assembly and an eccentric, adjustable diameter reamer are disclosed. The reamer includes cutter elements mounted on at least a first fixed blade for reaming a previously-formed borehole or for forming a borehole of increased diameter beneath an existing cased borehole. The method and apparatus provide for stabilizing the drilling assembly so that the reamer may be used in back reaming the hole. Retainer means, such as shear pins or spring-biased reciprocating latch members, are provided to prevent premature extension of the reamer's moveable members, including blades and pistons. The shear pins are preferably accessible from the outer surface of the reamer housing so as to expedite field replacement of the shear pins without requiring disassembly of the reamer. The spring-biased latching members repeatedly latch and unlatch so that field replacement is not required, and so that the movable members may be extended and contracted multiple times while the reamer is downhole.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.