Annulus cementing and washout systems for wells
US4856592A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1987 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | Dec 16, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/14
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An annulus cementing and washout technique and equipment, particularly for use in an offshore oil or gas well. An annulus is formed between an outer casing and a second-outer casing, this annulus being filled with cement up to a predetermined level and washed free of cement above said level. The second-outer casing is fitted with a washout casing section having washports at the predetermined level. The washports are selectively opened and closed by axially moving a hollow sleeve mounted in the washout casing section, preferably by turning the sleeve on a screw thread using a remotely operated tool. Details of a suitable tool include spring-loaded radial dogs which engage axial slots within the sleeve. Use of the sleeve and the tool to move the sleeve enables the washports to be opened and closed as required without troublesome rotation or support of the casing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.