Method and apparatus for maintaining a fluid column in a wellbore annulus
US6622798B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 2002 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | May 8, 2022 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/14
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and apparatus for maintaining the fluid column in an annulus are provided. The fluid column support, or fluid column seal is disposed about a second casing being lowered into a well through a first casing already cemented in the well. The fluid column support includes a seal connected to the second casing that engages the first casing as it is lowered therethrough. The seal will allow flow in an upward direction but prevents downward flow. The seal will support, or maintain a fluid column in the annulus between the first and second casing in the event that the fluid level below the seal drops for any reason, such as lost circulation or the failure of a buoyancy chamber in the second casing. The fluid seal, in conjunction with stage tools, provides hydrostatic pressure in the well to maintain proper fluid placement therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.