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Unformatted text preview: the wellbore, and the rig crew could not pull the pipe free. 24 The crew, therefore, had to sever the drill pipe and drill a bypass around the portion of the well with the stuck pipe. 25 The well also experienced several “lost return” incidents during drilling, when drilling mud pumped down the wellbore did not return to the surface as expected because some volume of the mud flowed into and was lost in the formation. 26 Lost returns are not uncommon and can occur for a variety of reasons, such as a fracture in the formation or drilling in overbalanced conditions. 27 Because of these and other challenges, on April 20, 2010, the Macondo well was about 38 days behind schedule and approximately $58 million over the original budget. 28 MC 252 Well Activity Report, 10/25/2009. IADC Reports, 3/8/10 ‐ 3/12/10. 25 A bypass is a secondary wellbore drilled away from the original hole. It is not uncommon for an operator to drill a bypass while experiencing problems during the drilling of a well. 26 IADC Reports, 3/8/10 ‐ 3/12/10. 27
As discussed throughout the Report, the lost returns at the Macondo well were of note because of their frequency and because they occurred along with other...
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