Rolling cone bit with enhancements in cutter element placement and materials to optimize borehole corner cutting duty
US5833020A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1996 |
| Grant date | Nov 10, 1998 |
| Priority date | — |
| Expiry date | Jun 21, 2016 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/52
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A rolling cone bit includes a cone cutter having a pair of adjacent rows of cutter elements that are positioned so as to divide the sidewall and bottom hole cutting duty. The wear resistance, hardness and toughness of the cutter elements in the adjacent rows are optimized depending upon the type of cutting the respective rows perform. In most applications, the cutter elements experiencing more sidewall cutting will have cutting surfaces that are more wear resistant or harder than the cutting surfaces of cutter elements in rows experiencing more bottom hole duty. Likewise, the cutter elements exposed to more bottom hole duty will generally be tougher than those experiencing substantial sidewall cutting. The material enhancements include varying the grades of tungsten carbide used in the cutter elements and by selectively employing layers of super abrasives, such as PCD or PCBN. The cutter elements may be either inserts or steel teeth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.