Yesterday, we learned that a procedure to prevent any more oil from spilling with a cement plug appears to have succeeded.

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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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And following the intersection of the well bore with those relief wells, they will put heavy mud down there to suppress the pressure of the oil coming up from the reservoir, put a cement plug in and effectively do what I would call a bottom kill, as opposed to the top kill, which was not successful a couple of weeks ago.

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It matters not how good the cement job or the plug and cement for abandonment, both cement and casing will deteriorate over time and eventually fail.

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In early August, owner BP used cement and mud to plug the damaged Gulf of Mexico well.

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This is usually a mechanical plug with cement poured in on top.

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