Blowout preventer control systems

Offshore, well control equipment and associated operations present some differences from that seen and used onshore. In some instances onshore equipment can be employed, but the offshore environment generally dictates a modification of equipment and procedures. There are several different well configurations used offshore, often on the same well at different drilling intervals, and each configuration has specific well control procedures that should be followed. A well may be equipped with a surface blowout preventer stack a subsea blowout preventer stack, riser and diverter system a riser and diverter system with no blowout preventer a diverter only or a riserless system with no well control equipment. 

The most common cause of a well to become uncontrolled and develop into a blowout is improper mud control operations and the inability of the blowout prevention system to contain it because of system failures, i.e., lack of testing and maintenance. 

A blowout prevention (BOP) assembly and well control system was installed before drilling below any casing string or during workover operations. [ 112.10(d)] ... 

Transocean was responsible for operation of the drilling rig and for the safety of operations, and to maintain well control equipment. Transocean purchased, maintained and operated a range of subsea equipment, including the blowout preventer (BOP) and associated control systems. 

Cai et al. (2013) discuss the use of BNs to assess the maintenance of subsea Blowout Preventer (BOP) control systems. Neil Marquez (2012) discuss the use of hybrid BNs the estimate the availability of renewable systems. Jones et al. (2010) apply BN modelling for maintenance planning in a manufacturing industry, while Melo Sanchez (2008)... 

A mechanism to rapidly close and seal off a well borehole, which is used to prevent a well blowout from occurring. It consists of rams and shear rams, usually hydraulically operated, which are fitted at the top of the well being drilled. It is activated if well pressures are encountered that cannot be controlled by the drilling process systems (i.e., drilling mud injection) and could lead to a blowout of the well. 

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