Method and apparatus for placing and cementing casing in horizontal wells
US5829526A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1996 |
| Grant date | Nov 3, 1998 |
| Priority date | — |
| Expiry date | Nov 12, 2016 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B43/10
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Improved methods and apparatus for placing and cementing a casing string in a horizontal well bore section are provided. A float shoe is attached to the end of the casing string and a float collar is connected in the casing string for trapping air in a first portion of the casing string thereby causing it to be buoyed up during placement by drilling fluid contained in the well bore. A selectively openable and releasable closed baffle assembly is connected within the casing string for trapping air or a low density fluid in a second portion of the casing string thereby causing it to also be buoyed up by drilling fluid in the well bore. The buoying up of the casing string reduces placement drag and consequent compressive loading on the casing string. After placement, the closed baffle means is opened to allow fluid circulation and conditioning of the annulus. A bottom cementing plug is then landed on the baffle assembly and the baffle assembly is released and moved to the float collar. A cement slurry is thereafter placed in the annulus and allowed to set therein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.