Annular Blowout Preventer

Annular Blowout Preventer usually a large gate equipped with a ram-type blowout preventer. During operation, a sealed annular space is formed between the pipe string and the wellbore. When there is no pipe string in the well, it is also The well can be shut-in alone, but it won’t work after several uses, and long-term shut-in use is not allowed.

1. What is the function of the annular blowout preventer?

⑴ When there is a pipe string in the well, a rubber core can be used to seal the annular space formed by the pipe string and the wellhead;

⑵The well head can be completely sealed when the well is empty;

⑶During the process of drilling, milling, casing grinding, logging, and salvage of falling objects, if overflow or blowout occurs, it can seal the space formed by the kelly, cable, wire rope, tools and wellheads for handling accidents;

⑷With the cooperation of pressure reducing and regulating valve or small accumulator, it can forcibly lift and lower the 18°butt-welded pipe string joint without fine buckle;

⑸In case of severe overflow or blowout, it is used to cooperate with ram blowout preventer and choke manifold to achieve soft shut-in.

2, what should be paid attention to when starting and running the drilling tool when shutting in with the annular blowout preventer?

(1) Only allow 18-degree butt-welded drill pipe joints without fine buckle.

(2) During the tripping process, there is a small amount of leakage between the rubber core and the drill pipe, which is not only allowed, but also necessary. A small amount of leaking drilling fluid can lubricate and cool the rubber core and improve the life of the rubber core. If necessary, lubricating fluid can be added to the top of the rubber core to lubricate the rubber core.

(3) The starting and descending speed must be slow, especially when passing the joint.

3, the working principle of the annular blowout preventer

Working principle of tapered rubber core annular blowout preventer

When the conical rubber core annular blowout preventer shuts in, the pressure oil from the hydraulic control system enters the lower oil chamber (closes the oil chamber) and pushes the piston to move up quickly. The rubber core cannot move up due to the restriction of the top cover. Under the action of the surface, it is forced to squeeze and shrink the drill tool toward the center of the wellbore, encircling the drilling tool, and seal the annular space of the wellhead. When there is no drilling tool in the well, the rubber core is squeezed toward the center and contracted until the hollow part of the rubber core is filled with rubber, thereby completely sealing the wellhead. At the same time, the hydraulic oil in the upper oil chamber flows back to the oil tank through the hydraulic control system pipeline.

When opening the tapered rubber core annular preventer, the pressure oil from the hydraulic control system enters the upper oil chamber (opening the oil chamber) to push the piston down quickly. The squeezing force of the inner cone of the piston against the rubber core quickly disappears, and the rubber core expands outwards by the elasticity of its own rubber to restore its original shape, and the well head is fully opened. At the same time, the hydraulic oil in the lower oil chamber flows back to the oil tank through the hydraulic control system pipeline.

Spherical packing element      

Conical packing element

Codes Description of Annular BOP

Product Code

FH-D  Annular BOP using the Spherical packing element

FH-A  Annular BOP using the Conical packing element

FH-D 7 1/16″-3,000psi Annular BOP (With Spherical Rubber)

FH-D 7 1/16″-5,000psi Annular BOP (With Spherical Rubber)

FH-D 9″-3,000psi Annular BOP (With Spherical Rubber)

FH-D 9″-5,000psi Annular BOP (With Spherical Rubber)

FH-D 11″-2,000psi Annular BOP (With Spherical Rubber)

FH-D 11″-3,000psi Annular BOP (With Spherical Rubber)

FH-D 11″-5,000psi Annular BOP (With Spherical Rubber)

FH-D 13 5/8″-3,000psi Annular BOP (With Spherical Rubber)

FH-D 13 5/8″-5,000psi Annular BOP (With Spherical Rubber)

FH-D 18 3/4″-5,000psi Annular BOP (With Spherical Rubber)

FH-D 20 3/4″-3,000psi Annular BOP (With Spherical Rubber)

FH-D 21 1/4″-5,000psi Annular BOP (With Spherical Rubber)

FH-A 7 1/16″-10,000psi Annular BOP (With Tapered Rubber)

FH-A 11″-10,000psi Annular BOP (With Tapered Rubber)

FH-A 11″-15,000psi Annular BOP (With Tapered Rubber)

FH-A 13 5/8″-5,000psi Annular BOP (With Tapered Rubber)

FH-A 13 5/8″-10,000psi Annular BOP (With Tapered Rubber)

FH-A 16 3/4″-3,000psi Annular BOP (With Tapered Rubber)

FH-A 16 3/4″-5,000psi Annular BOP (With Tapered Rubber)

FH-A 21 1/4″-2,000psi Annular BOP (With Tapered Rubber)

API 16A Single Ram BOP and Double Ram BOP

The RAM Blowout Preventer is mainly used in workover and drilling operations with varied technical requirements. With a BOP body,side outlet, ram body, and other pressure bearing parts crafted from defect-free forged metal, and an oval-shaped inner chamber to reduce stress concentration and improve its sealing performance, this BOP can efficiently prevent an oil well blowout.The double ram BOP can be equipped with different types of rams, such as pipe ram, blind ram, shear ram or variable diameter ram, to meet different applications.

The ram seal is a float type, which will decrease the resisitance and abrasion of the rubber core.The service life is greatly prolonged. Its anti-H2S performance conforms to NACE MR 0175 standard.

• Ram BOP seals annular space between tubing and casing or wellbore.
• Ram BOP suspends and stabilizes string.
• Ram BOP with side outlets could be used for choke and blowout.
• Ram BOP can be used in operation under pressure.