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VII. Temporary Abandonment of the Macondo Well

At the end of drilling operations, the rig crew needs to secure the well
prior to leaving the site. “Temporary abandonment” refers to the process by
which the rig crew installs cement plugs in the well and pulls the riser and
blowout preventer to the surface to move to another location. Pressure testing
(called positive and negative tests) is a key component of temporary
abandonment procedures because it seeks to ensure well integrity and that
hydrocarbons are not leaking into the well.

A. Installing the Lock‐Down Sleeve

BP’s planned temporary abandonment procedures for the Macondo well
were not completed until April 12, and subsequently changed a number of times
before April 20. The initial plan included the setting of a lock‐down sleeve prior
to displacing drilling mud from the riser.

Temporary abandonment procedures do not always include installation of
a lock‐down sleeve. Correspondence from late 2009 and early 2010 shows that
BP decided to install the lock‐down sleeve as part of its temporary abandonment
procedures on the Macondo well to save costs. In January 2010, Merrick Kelley,
BP subsea wells team leader, exchanged a number of emails with BP drilling
engineer Mark Hafle about the installation of a lock‐down sleeve by the
Deepwater Horizon crew. Kelley calculated that this would save $2.2 million in
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incremental costs:

199 BP‐HZN‐MBI‐00097490.

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