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of the ram blocks; and (5) function testing of critical functions and circuits that
were involved in the attempts to control the well during the first two days
338
following the blowout.

3. Materials Evaluation and Damage Assessment

Another critical part of DNV’s forensic work was materials evaluation and
damage assessment. Materials evaluation included: (1) cleaning and examining
the BOP rams; (2) cleaning and examining drill pipe segments removed from the
BOP stack and the riser; (3) cleaning and examining components extracted
during the removal of the rams; and (4) collecting and cleaning all solid objects
found within the different ram cavities.

DNV assessed the damage to the BOP stack in three different ways: (1)
visual inspection and photo documentation; (2) dimensional measurements; and
(3) three‐dimensional laser scanning. In addition, DNV used structural analysis
339
and modeling to simulate drill pipe behavior in the wellbore.

4. ROV Intervention Operations Review

DNV reviewed video footage and still photographs taken from a number
of different ROVs that were used during attempts to stop the well flow. This
review allowed DNV to assess the condition of the BOP stack when it was still
submerged and to try to determine the origin of leaks in the BOP’s hydraulic
circuitry. This review also allowed DNV to assess the impact of various ROV
340
interventions on the condition of the BOP stack.

H. DNV’s Forensic Examination Findings

DNV’s forensic examination found that, as the BSR was closed, the drill
pipe was positioned such that the outside corner of the upper BSR blade
contacted the drill pipe slightly off center of the drill pipe cross section. A
portion of the pipe cross section was outside of the intended BSR shearing
surfaces and would not have sheared as intended. As the BSR closed, a portion
of the drill pipe cross section became trapped between the ram block faces,
preventing the blocks from fully closing and sealing.

338 DNV Report, Vol. 1, at 23‐24.
339 Id. at 23.
340 Id. at 24.

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