Method of circulating while retrieving bottom hole assembly in casing
US8176986B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2009 |
| Grant date | May 15, 2012 |
| Priority date | — |
| Expiry date | May 28, 2030 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B33/068
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Retrieving a down hole tool at a lower end of a string of casing can be performed with drill pipe during a casing-while-drilling operation. The operator suspends the casing on a landing sub landed in a drilling rig floor opening. A string of drill pipe is lowered into the casing while the casing is suspended for engaging and retrieving the down hole tool. A spillage preventer in the landing sub prevents spillage of drilling fluid as the drill pipe is being retrieved. When circulation is desired, the operator secures a circulation tool to an upper end of the drill pipe, then lowers the drill pipe and the circulation tool to close off an upper end of an inner annulus between the drill pipe and the casing. A connection between the circulation tool and the landing sub allows the operator to reciprocate the casing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.