Annulus check valve with tubing plug back-up
US6186237A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1998 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | Oct 2, 2018 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/117
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A subsea well has a tubing hanger which has an annulus bore and a production bore. A check valve is located in the annulus bore. A running tool runs the tubing hanger on a monobore riser such as a drill string while holding the check valve in the open position. After setting and testing, the running tool is lifted and a blowout preventer is closed around the landing string. The operator monitors the choke and kill line of the drilling riser, which will be in communication with the check valve. If the check valve is leaking, an annulus plug may be installed in the annulus bore. The installation of the annulus plug may be handled by using a retrieval tool configured to align the annulus bore with the landing string passage. A wireline tool may be lowered through the landing string and retrieval tool to retrieve the check valve and install the plug. Alternately, the check valve may remain in the tubing hanger and the plug is set in the annulus bore above it. The check valve is retained in the open position, if so.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.