Blowout preventers are large, high-pressure valves that are capable of being remotely controlled. When the driller closes the valve, a pressure-tight seal is formed at the top of the well, preventing the fluids from escaping. There are two major types of Blowout Preventers, Annular BOP and Ram BOP. Annular BOPs are usually mounted to the very top of the BOP stack. The drilling crew then mounts two, three, or four RAM BOPs below the Annular preventer. If a kick is detected, the annular is usuall