Device for suspending a sub sea oil well riser
US5778981A · kind A · utility
Inventor
Key dates
| Filing date | Jul 29, 1996 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Jul 29, 2016 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B41/10
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The invention relates to a guide arrangement 1 for a riser assembly 10 including a length of a second riser tube 6 running from a well head 2 to a surface vessel 6. First buoys 8 are provided which permit the evacuation and refilling of water to adjust the buoyancy effect and comprise a system to admit a controlled amount air or water and which are connected to the lower end of the riser assembly 10 by a first line 14 via a pulley 16 such that as the first buoys are raised the riser assembly 10 is pulled downwards towards the well head. Second buoys are provided to form a rigid frame work for the guide arrangement 1 when air has replaced the water contained therein. Support buoys 22 are connected to the first and second riser tubes 4, 8 by air line tubes 13 which enable air to be removed from and added to the support buoys 22 to adjust the amount of buoyancy they provide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.