Methods and apparatus for creating a downhole buoyant casing chamber
US6505685B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2000 |
| Grant date | Jan 14, 2003 |
| Priority date | — |
| Expiry date | Aug 31, 2020 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/10
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Methods and apparatus for creating a downhole buoyant casing chamber. The buoyant casing chamber may be created after the casing has been at least partially run into the wellbore. Some embodiments also allow circulation of fluid as the casing is being run after the creation of the buoyant chamber. A method of the invention comprises running a length of casing into the well to a first step, forming a buoyant chamber in the casing, filling the chamber with buoyant fluid, either a gas or a light liquid, and running the casing to a second depth greater than the first depth. The apparatus used comprises a length of casing, a floating device disposed in a lower end of the casing and forming a lower boundary of a buoyant chamber, a packer for sealingly engaging the casing in an upper end of the buoyant chamber, and a volume of buoyant fluid to fill the chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.