The blowout preventer consists of a series of complex valves that are designed to facilitate shutting of a oil well if the flow of oil increases massively all of sudden. In case the well is not shut, it can destroy the entire drilling equipment and risk casualties.
The blowout preventer is used in only in oil production wells offshore, where it is difficult to gauge flow of oil production and sometimes oil comes up in gushers.
The blowout preventer comes in different styles and shapes, depending on the need. The function of all designs and styles is nevertheless same, that to facilitate closing of an oil well as soon as there is an uneven flow of oil out of the production well, especially if there is rapid increase in the oil production.
The valves fit on the preventer can be opened and closed manually or hydraulically. Modern blowout preventer are automated equipments and can be operated through remote control centres. The new methods are rather time efficient and their response rate is far better than those used in early days, which were not automated.
Each preventer has a different number of valves attached to. It can be four and sometimes up to 10, depending on the requirement and the level of automation used. Generally, the preventers are secured with pipes underneath the sea water, mainly the drilling pipes, which also suck the oil out of the wells.