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4. The Agency should consider promulgating regulations that require at
least two barriers (one mechanical and one cement barrier) for a well that
is undergoing temporary abandonment procedures. As seen in this
474
event the only barrier between the rig and the formation was a cement
plug in the shoe track. Having a cement plug and an additional
mechanical barrier would add an increased safety factor. While the
Macondo well did have dual float valves, the Panel does not believe that
float valves should be considered a mechanical barrier.
475

5. The Agency should consider revising 30 CFR § 250.420(b)(3), which is
included in the Interim Final Rule, to clarify that a float collar/valve is not
to be considered to be a “mechanical barrier.” Float collars are designed
to prevent the cement from u‐tubing back into the work string; they are
not designed to keep the formation pressures from coming up the
wellbore. A dual float valve was used in the Macondo well. Clarifying
the limitations of the float collar would prevent operators from relying on
a device not designed specifically for pressure containment.
476

6. The Agency should research and consider defining “lost returns,” “partial
returns,” “full returns,” and “cement volume margin” within 30 CFR §
250.428. As seen in this event, lost returns played a large role in
accurately determining hole stability and cement placement. However,
the regulations do not define what is considered lost returns.

B. Kick Detection and Response Recommendations

1. The Agency should consider issuing a Safety Alert similar to Safety Alert
284 that addresses how the movement of fluid across the rig can limit the
monitoring capabilities of rig personnel. As discussed in the Report, the
multiple simultaneous operations involving fluid movement that were

474 This recommendation was incorporated into the regulations with the interim final rule
effective October 14, 2010.
475 This recommendation was incorporated into the regulations with the interim final rule
effective October 14, 2010.
476 30 CFR § 250.420 was revised with the interim final rule to require two barriers. This revision
allows for the use of a dual float valve or one float valve and a mechanical barrier in addition to
the cement. The Panel recommends that the agency should not allow the use of float valves as a
mechanical barrier.

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