The team then failed to run a test to establish that the cement seal was adequate.

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Most of the technical issues covered in the report, such as the failure of a crucial cement seal and the misinterpretation of a key pressure test, have been raised by other investigations.

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Cement used to seal the well was provided by Halliburton.

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From that point, it will take another few days to permanently seal the well with mud and cement from below in what's called a "bottom kill" procedure.

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McMoran took over Blackbeard West some years ago and found hydrocarbons about 2500 feet below the point where Exxon Mobil gave up and poured cement down the hole to seal it.

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If a stable column of mud has been set up in the well, keeping the oil at bay through its sheer weight, the next step would be to set cement in the well and seal it off permanently.

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Cement forms an extremely strong, effectively impermeable, seal from a thin slurry that can be pumped pretty easily anywhere, and is the ideal material for this purpose ( Cementing).

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Given the two red flags that had been thrown up previously, one would have expected that as a precaution a cement plug would have been placed somewhere in the wellbore as a secondary pressure seal before this primary pressure control system (heavy mud) was evacuated from the wellbore.

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