Slip joint intervention riser with pressure seals and method of using the same
US6173781A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1998 |
| Grant date | Jan 16, 2001 |
| Priority date | — |
| Expiry date | Oct 28, 2018 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B19/006
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A pressurized slip joint for a marine intervention riser decouples the flowhead assembly in the moon pool of a vessel from the riser string, enabling safe changeover of equipment during workover operations. One part of the slip joint assembly is coupled to the flowhead assembly through a flexible joint assembly. A second part of the slip joint assembly supports the riser string and is coupled to the tensioning mechanism. The first part may be inserted into the second part and locked in place during workover operations except when equipment changeover is taking place. When changeover is being carried out, the first and second parts are unlocked, so that the flowhead assembly does not move relative to the vessel. In the locked position, a metal-to-metal high pressure seal, with a secondary and tertiary seal controls the pressure in the riser. In the unlocked position, a hydraulically operated dynamic low pressure seal is used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.