Device for anchoring an oil well tubing string within an oil well casing
US6318459A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 1999 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Aug 9, 2019 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B23/01
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An anchoring device for anchoring an oil well tubing string within an oil well casing. The device generally comprises a drive mandrel and an anchor mandrel. The drive mandrel has an upper end and a lower end, with the upper end releasably securable to an oil well tubing string. The anchor mandrel has an upper end that is releasably securable to the drive mandrel. The anchor mandrel is selectively engagable and disengagable with the interior surface of an oil well casing through the use of a plurality of rotatable slips. The slips have a gripping surface to contact and adhere to the interior surface of the oil well casing such that when the anchor mandrel is rotated in a first direction the slips are rotatably deployed to an engaged position with the gripping surfaces in contact with the interior surface of the oil well casing. Rotation of the anchor mandrel in a second opposite direction causes the slips to be rotatably retracted from their engaged position to a disengaged position such that the gripping surfaces are withdrawn from contact with the interior surface of the oil well casing. A shear mechanism may be employed between the drive and anchor mandrels to alow for controled …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.