Drill string splined resilient tubular telescopic joint for balanced load drilling of deep holes
US4434863A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 1980 |
| Grant date | Mar 6, 1984 |
| Priority date | — |
| Expiry date | Dec 16, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/07
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drill string splined resilient tubular telescopic joint for balanced load deep weel drilling comprises a double acting damper having a very low spring rate upon both extension and contraction from the zero deflection condition. Stacks of spring rings are employed for the spring means, the rings being either shaped elastomer-metal sandwiches or, preferably, roller Belleville springs. The spline and spring means are disposed in an annular chamber formed by mandrel and barrel members constituting the telescopic joint. The chamber containing the spring means, and also containing the spline means, is filled with lubricant, the chamber being sealed with a pressure seal at its lower end and an inverted floating seal at its upper end. A prototype includes of this a bellows seal instead of the floating seal at the upper end of the tool, and a bellows in the side of the lubricant chamber provides volume compensation. A second lubricant chamber is provided below the pressure seal, the lower end of the second chamber being closed by a bellows seal and a further bellows in the side of the second chamber providing volume compensation. Modifications provide hydraulic jars.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.