![]() ![]() ![]() This condition would have most likely occurred from the moment the well began flowing and would have remained until either the end conditions changed (change in Upper Annular or Upper VBR state) or the deflected drill pipe was physically altered (sheared). The drill pipe deflected until it contacted the wellbore just above the blind shear rams (BSRs). The drill pipe was then fixed but able to pivot at the Upper Annular, and horizontally constrained but able to move vertically at the Upper VBRs.įorces from the flow of the well induced a buckling condition on the portion of drill pipe between the Upper Annular and Upper VBRs. This created a fixed point arresting further upward movement of the drill pipe. With both the Upper Annular and the Upper VBRs closed on the drill pipe, forces from the flow of the well pushed the tool joint into the Upper Annular element. Evidence supports that the Upper VBRs were closed prior to the EDS activation at 21:56 on April 20, 2010.Ī drill pipe tool joint was located between the Upper Annular and the Upper VBRs. Measurements of the ST Lock positions performed at the Michoud facility confirmed that both ST Locks on the Upper VBRs were closed. ![]() Scans of the starboard side ST Lock on the Upper VBRs were inconclusive. ROV gamma ray scans on May 10, 2010, confirmed that the ST Lock on the port side Upper VBR was closed. There was no documented means of ROV intervention to close the Upper VBRs. The Upper VBRs were found in the closed position as-received at the Michoud facility. This was the final recorded well control attempt from the surface before the rig was abandoned at 22:28. At 21:56 the Emergency Disconnect Sequence (EDS) was noted to have been activated from the bridge. The first explosion was noted as having occurred at 21:49. At 21:47 the standpipe manifold pressure rapidly increased from 1200 PSIG to 5730 PSIG. Approximately 30 minutes after the conclusion of the second leak-off (negative pressure) test, fluids from the well began spilling onto the rig floor. Prior to the loss of well control on the evening of April 20, 2010, the Upper Annular (UA) was closed as part of a series of two negative or leak-off tests. Photo courtesy of the Deepwater Horizon Joint Investigation Team ![]()
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