Shallow flow wellhead system
US5660234A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Feb 1, 1996 |
| Grant date | Aug 26, 1997 |
| Priority date | — |
| Expiry date | Feb 1, 2016 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B34/04
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A subsea wellhead system is used in areas which have shallow water producing sands. A first string of casing extends from the sea floor through a section of conductor pipe and below the conductor pipe to a point above the water sand. An external wellhead housing having flow ports is supported at the upper end of the conductor pipe. A valve sleeve is located on the exterior of the external wellhead housing. The valve sleeve is movable to a closed position, closing the flow ports. A second string of casing is installed to a point below the water producing formation. An internal wellhead housing is secured to the upper end of the second string of casing, which lands within the external wellhead housing. During cementing of the second string of casing the flow ports are open. After cementing, the valve sleeve is moved to the closed position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.