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Blowout Preventer

Blowout PreventerOne or more valves installed at the wellhead to prevent the escape of pressure either in the annular space between the casing and the drill pipe or in open hole (for example, hole with no drill pipe) during drilling or completion operations. See annular blowout preventer and ram blowout preventer.*

*This is an abridged version of the Dictionary of Petroleum Terms used with permission from PETEX®, The University of Texas, at Austin. All rights reserved © PETEX 2001.