Preventer (BOP) devices are typically installed on the top of the
casing, below the rig floor. BOPs are large valves that help contain the liquid
and gas pressure in the well.
One type of BOP can seal off the annulus, the
space between the drill pipe and the casing, if the drill pipe is still in the
hole. Another can shear off the drill pipe and thus seal off the entire well if
no drill pipe is in the hole. Usually, several of these BOPs are mounted as a
Read more about
the role of Blowout Preventers in the Stages
Petroleum Communication Foundation. Our Petroleum Challenge: Exploring Canada's Oil and Gas Industry, Sixth Edition. Calgary: Petroleum Communication Foundation, 1999. With permission from the Centre for Energy.