The float shoe prevents reverse flow, or U-tubing, of cement slurry from the annulus into the casing.

浮鞋能够防止环空中的水泥浆向套管内流动这种回流或者U型管效应的发生。

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A float collar is placed at the top of the float joint and a float shoe placed at the bottom to prevent reverse flow of cement back into the casing after placement.

浮箍是放置于浮动接头之上的，而浮鞋则是放置于浮动接头之下，以防止水泥浆回流到套管内。

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The denser mud had been, up until this time, the primary pressure control and was keeping the hydrocarbons in place despite the lack of an adequate cement job at the casing shoe.

WSJ: The Oil Disaster Is About Human, Not System, Failure