Javascript is needed for displaying rollover states on the navigation buttons but otherwise the hyperlinks function.
eTools Home :Oil and Gas Well Drilling and Servicing eTool Credits
 
Job Safety Analysis (JSA)
Drilling >> Well Control >> Blowout Preventers

The second line of defense for the workers and the well to prevent a blowout is the group of equipment called blowout preventers (BOPs). BOPs and associated valves are installed on top of the casing head before drilling ahead after rigging up. These high-pressure safety valves and associated equipment are designed to shut off the well hole and prevent the escape of the underground fluids and prevent a blowout from occurring.

After installation, the BOP and associated valves are pressure tested to insure integrity and proper operations.

The BOP and associated equipment consists of:
Fig. 1. Blowout preventer stack
Fig. 1. Blowout preventer stack

Back to Top BOP Stack
Fig. 2. A blowout preventer (BOP) with one annular BOP on top and two ram type BOPs are stacked together with a kill line valve and a choke line valve.
Fig. 2. A blowout preventer (BOP) with one
annular BOP on top and two ram type BOPs
are stacked together with a kill line
valve and a choke line valve.



A BOP installation could consist of both annular and ram-type BOPs assembled into a stack. Also, there can be a kill line valve and a choke line valve.

The choke line valve is used to redirect the mud from the well bore to the choke manifold during a kick.

The kill line valve is used to direct drilling fluid to the BOP during a kick.





Back to Top Annular BOP
Fig. 3. Annular blowout preventer cutaway diagram showing the head, piston, wear plate, packing unit, opening chamber, and closing chamber.
Fig. 3. Annular blowout preventer cutaway diagram showing the head, piston, wear plate,
packing unit, opening chamber, and closing chamber.



Annular BOPs are designed to form a seal in the annular space between the drill pipe and the wellbore and are usually mounted at the top of the BOP stack.





Back to Top Ram-Type BOP
Fig. 4. Ram-type blowout preventer
Fig. 4. Ram-type blowout preventer



Ram-type BOPs have rubber faced steel rams that come together with great force to seal the wellbore. Usually two or more ram-type BOP's are mounted in the BOP stack.





Back to Top Choke Manifold
Fig. 5. Choke manifold
Fig. 5. Choke manifold



A choke manifold is a system of valves used to circulate out a kick and to circulate mud in of the proper weight. This device responds automatically to a kick and can prevent a blowout if properly installed and maintained.





Back to Top Accumulator
Fig. 6. The blowout preventer control systems accumulator showing regulator valves, accumulator bottles, back-up pump (pneumatic), hydraulic reservoir, control manifold, control valves, and pump (electric, gas, diesel).
Fig. 6. The blowout preventer control systems accumulator showing regulator valves, accumulator bottles, back-up pump (pneumatic), hydraulic reservoir, control manifold, control valves, and pump (electric, gas, diesel).

The BOP control system, called an accumulator, provides the energy to operate the blowout preventers.


This system of consists of:
  • Compressed gas bottles,

  • Regulator valves,

  • Pumps,

  • Hydraulic reservoir,

  • Control manifold, and

  • Control valves.


eTools Home :Oil and Gas Well Drilling and Servicing eTool Credits