Spar system
US6210075A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 1999 |
| Grant date | Apr 3, 2001 |
| Priority date | — |
| Expiry date | Jan 21, 2019 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/035
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An offshore hydrocarbon production system includes a spar (34, 52, 214) that floats at the sea surface, a subsea buoy (26, 154, 200, 210) lying under the spar and hanging from it, and one or more risers (20, 174, 220) that extend up to the subsea buoy and are coupled therethrough to the spar. The subsea buoy is initially negatively buoyant to ballast of the spar and keep it upright, but the subsea buoy can be made positively buoyant so the spar can be moved away and a workover vessel (70) moved over the subsea buoy. The subsea buoy can be coupled to the spar by one or more chains (60, 60A) extending between them, and one or more flexible hoses (60) extending between them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.