Circulating cementing collar and method
US6810958B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2001 |
| Grant date | Nov 2, 2004 |
| Priority date | — |
| Expiry date | Feb 21, 2022 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B2200/05
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An apparatus and method for cementing a casing string in a wellbore. A self-filling tubular cementing collar connected to the lower end of a casing string is provided with one-way flow valving that allows well fluid to enter and self-fill the casing string as it is lowered into the wellbore and automatically prohibits reverse fluid flow from the collar when washing or cementing during forward circulation through the collar. The one-way valving is carried by an axially movable support that can be shifted by a cementing plug moved by pump pressure to permanently seal the entry flow passage after the casing sting is properly positioned in the wellbore.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.