Downhole string for drilling through a low pressure zone
US10253591B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 19, 2015 |
| Grant date | Apr 9, 2019 |
| Priority date | — |
| Expiry date | Jul 14, 2035 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/06
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The present invention relates to a downhole string (1) for drilling through a low pressure zone (Zlow) in a formation (45) in a well (3), comprising a drawdown casing (2) having a first end (4) closest to a top (5) of the well and a second end (6), and an operational tool (8) connected to the second end of the drawdown casing, wherein the downhole string further comprises an annular barrier (10) having an expandable metal sleeve (11) surrounding the drawdown casing, each end of the expandable metal sleeve being connected with the drawdown casing, the expandable metal sleeve being adapted to contact a wall (16) of a borehole (17) or another casing so that the drawdown casing can rotate and slide in relation to the annular barrier after expansion of the expandable sleeve. Furthermore, the present invention relates to a downhole system and to a downhole method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.