Teams must be careful that the mud does not raise pressure too high and cause possible damage to the well pipe.

工程人员必须保证压力不能过大，避免引发对油井管道造成可能的破坏。

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On May 26th BP started to pump heavy drilling mud into the blowout preventer, the set of valves at the top of the well to which that broken pipe is attached.

5月26日，英国石油公司开始将重型钻探泥浆用泵抽运进防喷装置- - - - -它是由多个气阀构成，位于油井顶部，连接着那根已断裂的立管。

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This pressure must be under control, and we control it by means of the mud which we circulate down the drill pipe.

这种压力必须加以控制，我们让泥桨顺着钻杆向下循环，用这种方法来控制压力。

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The friction caused by the gas bubble pushing up the pipe and displacing the drilling mud used to control the pressure could have created a static charge that ignited the gas into a fireball.

FORBES: BP's Deepwater Disaster: What Happened And Why?

At 8:20 p.m. on the day of the explosion the pressure data suggest there was a constant flow of sea water being pumped into the drill pipe that was displacing the heavier mud system which was the primary pressure control for the well.

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