What is annular BOP?

Dec. 21, 2022

Annular BOP – Well Control Equipment

The annular BOP is named for its sealing element, the rubber core ring. Also known as the universal blowout preventer, multi-performance blowout preventer, or spherical blowout preventer. The annular BOP is an important well control device in the oil drilling field. It carries a lot of weight to prevent leaks or disasters.

What is annular BOP?

Designed for safe good pressure control during drilling and workover operations, the Annular BOP is a large valve designed to seal, control and monitor oil and gas wells. The valve rotates during drilling to maintain a seal around the drill pipe. The Annular BOP helps to maintain a good seal on the oil to prevent catastrophic blow-outs.

Annular BOP is usually fitted with a large gate of a ram BOP, which is operated to create a sealed annular space between the pipe string and the wellbore. It can also seal a well alone without the pipe string in the well, but it will not work after several times of use, and it is not allowed to shut down the well for a long time.

annular bop parts

The Annular BOP consists of a valve body, upper housing, sealing elements, dust ring, and piston.

When the well contains drill, tubing, or casing, the annular BOP can be enclosed with a single core that encloses annular Spaces of various sizes. When there is no drilling tool, it can completely close the wellhead for drilling, coring, logging and other operations. It can also close the annular space formed by the kelly pipe, coring tool, cable and steel wire and the wellbore. Under the condition of using the decompression and pressure regulating valve, it can force the drilling tool down through the drill pipe.

annular bop type

Annular BOP can be classified into the following three types according to the shape of the core: conical annular BOP, spherical annular BOP and combined annular BOP. Conical and spherical rubber core annular blowout preventers work similarly: When it is found that a kick needs to be sealed, the high-pressure oil from the control system enters the lower closing chamber of the piston from the lower oil port to push the piston to move upward. The spherical rubber core moves upward along the spherical surface, while the cone rubber core moves down to the center under the restriction of the top cover and the extrusion action of the inner cone of the piston, and then tightens and encircle the drilling tool to seal the drilling tool or seal the wellhead completely. When the well is opened, the piston goes down and the rubber core resets and opens the wellhead under the action of its elastic force.

annular bop sizes

Annular BOP Bore Size: 13 5/8"

Rated Working Pressure: 3000psi～10000psi
Temperature Range for Metallic Materials: -59℃～+177℃
Temperature Range for Nonmetallic Sealing Materials: -26℃～+177℃
Performance Requirement: PR1、PR2

Annular BOP Bore Size: 16 3/4"

Rated Working Pressure: 3000psi～5000psi
Temperature Range for Metallic Materials: -59℃～+177℃
Temperature Range for Nonmetallic Sealing Materials: -26℃～+177℃
Performance Requirement: PR1、PR2