Dual-seal drill bit pressure communication system
US6196339A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1998 |
| Grant date | Mar 6, 2001 |
| Priority date | — |
| Expiry date | Nov 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S277/928
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A drill bit for use in a borehole at least partially containing drilling fluid includes a bit body having at least two bit components, including at least one leg, the leg having a journal segment, and a roller cone rotatably mounted upon the journal segment and forming at least one bearing cavity therebetween. Also included is an annular primary seal disposed between the leg and the roller cone and an annular secondary seal disposed between the leg and the roller cone and between the annular primary seal and the borehole. An annular space is defined between the annular primary seal and the annular secondary seal, the annular space at least partially containing fluid and being in substantially absolute fluid isolation from the bearing cavity. The seals are configured to allow the passage of a fluid from the annular space to the borehole. The annular secondary seal may be primarily elastomeric and a passage for fluid from the borehole to the annular space can be included. The annular space may at least partially include a grease possessing a water washout value of under approximately 50% per ASTM D-4049 water spray test for lubrication characteristics and the grease may include a pol…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.