Drill bit having offset roller cutters and improved nozzles
US4848476A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 1988 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Feb 29, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/52
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A triple cone drill bit (10, 10A) comprising a plurality of conical roller cutters (16, 16A) having hard metal cutting elements thereon and being so positioned relative to each other that their rotational axes are offset from the rotational axis of the drill bit (10, 10A), and a drilling fluid nozzle system for directing a pressurized fluid stream (76, 76A) across certain of the cutting elements and thereafter against the formation generally at the bottom of the well bore so that when the drill bit (10, 10A) is used in its most advantageous areas, such as the soft, medium-soft and plastic formations, the nozzle system prevents "balling up" of the cutters and greatly increases the drilling efficiency of the bit. In one embodiment (FIGS. 15-20) the drill bit body (12A) has vertically extending recessed portions (21A) formed at the junctures (19A) of the lugs (15A) to provide flow passageways for the upward flow of drilling fluid and entrained cuttings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.