Retrievable float valve assembly
US4393940A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1980 |
| Grant date | Jul 19, 1983 |
| Priority date | — |
| Expiry date | Oct 28, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/7426
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A retrievable float valve hanger tool assembly provides a hanger sub having a first upper connection for attaching the hanger sub, for example, threadably, to a drill string or work string. A second lower connection means on the sub provides both external and internal threaded (for example) connections, which allow the sub to be connected on its inner threads to a float valve canister and at its external threads to an extension which forms a protective housing about the float valve and its valve canister during operation. The device places the float valve below the joint of the sub and the extension so that an explosive charge can be detonated at the joint allowing easy removal of the float valve from the drill string in the event that the drill pipe becomes stuck. A continuous bore through the assembly allows fluid circulation through the tool in the work string and also allows the explosive charge to be lowered by wireline, for example, to the tool assembly at the appropriate joint. The explosive charge, detonated above the float valve aids in breaking the connection between the hanger sub and extension so that the float valve canister can be removed when the hanger sub and exten…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.