Cementing plug launching apparatus
USRE29830E · kind E · reissue
Assignee
Inventor
Key dates
| Filing date | Jan 20, 1975 |
| Grant date | Nov 14, 1978 |
| Priority date | — |
| Expiry date | Jan 20, 1995 |
Classification
- Technology area (CPC —)General
Abstract
Cementing plug launching apparatus for use in cementing a casing string in a well in which a casing closure is releasably attached to the upper end of the casing string, the closure having a cement conduit opening therethrough and in which a cementing plug is releasably supported below the closure by the cement conduit, the plug being separable from the cement conduit upon introduction of a ball into the cement flowing into the casing through the conduit. Such apparatus in which a combination of top and bottom plugs are releasably supported by the cement conduit, the bottom plug being releasable from the top plug in response to the introduction of a first ball into the cement flowing through the cement conduit into the casing and the top plug being released from the cement conduit in response to the introduction of a second ball into the cement flowing through the cement conduit into the well casing, a float shoe being provided at the lower end of the casing for arresting downward movement of the bottom and top plugs, respectively. Such apparatus in which the casing closure includes releasable latch means for latching the same to a well head structure at the bottom of a body of wat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.