| 摘要 |
Floating apparatus for well casing including a check valve disposed in a sleeve, wherein the sleeve is receivable within an outer case. In the case of a float collar, the outer case comprises coupled upper and lower casing string sections; while in the case of a float shoe, the outer case is individually coupled to a lower casing string section. The valve includes a valve housing, wherein a first cement body portion attaches the valve housing to the sleeve. When the embodiment of the invention is constructed as a float collar, the sleeve includes an annular flange that is outwardly extended therefrom and is received between ends of coupled upper and lower casing string sections for holding the sleeve and affixed valve within the outer case. A seal is provided between the flange and upper casing string section. Alternatively, when the embodiment of the invention is constructed as a float shoe, a second cement body portion attaches the sleeve to the outer case, thereby holding the sleeve and affixed valve within the outer case which is threadably connectable with the well casing. Preferably, the second cement body portion only partially fills an annulus between the sleeve and outer case, wherein the well casing is received in the annulus when threadably connected to the outer case.
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