Dual spring drill string shock absorber
US4186569A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 21, 1978 |
| Grant date | Feb 5, 1980 |
| Priority date | — |
| Expiry date | Feb 21, 1998 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/07
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A drill string shock absorber has a dual spring system for absorbing vibrations and shock loads during rotary well bore drilling operations. A first spring acts in compression when sufficient weight is set down on the drill bit through the shock absorber to overcome the fluid pressure forces tending to extend the shock absorber, and a second spring acts in compression when the weight applied to the bit through the shock absorber does not overcome the fluid pressure forces. A splined connection transmits torque to the shock absorber during drilling operations, and seals are provided between the telescopic shock absorber components for confining therein a body of lubricant, the pressure of which is equalized with the pressure of drilling fluid flowing through the shock absorber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.