Drilling rig equipped with pairs of block and tackle systems
US4423994A · kind A · utility
31Cited by
4References
34Claims
0Family size
Inventors
Key dates
| Filing date | Oct 26, 1981 |
| Grant date | Jan 3, 1984 |
| Priority date | — |
| Expiry date | Oct 26, 2001 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B19/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
This invention relates to drilling rigs, and more particularly to novel apparatus for supporting a plurality of pairs of block and tackle systems with the tackle systems of each pair operable sequentially and alternately, the one being used to support a main drilling or tubing string while the other is being used to rack stands of tubing therefrom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.