28-70 Double Ram Hydraulic Blowout Preventer

Blowout preventer is a critical well control device that plays a crucial role in drilling, especially in underbalanced drilling. The purpose of designing a blowout preventer is to close the wellbore under pressure, maintain continuous control of the well, and circulate the formation fluid entering the well

The hydraulic blowout preventer mainly includes double gate hydraulic blowout preventer and annular blowout preventer. The gate blowout preventer is mainly composed of a housing, side doors, oil cylinders, cylinder heads, pistons, piston rods, locking shafts, seals, gate plates, etc. Its working process is to use hydraulic pressure to push the piston, drive the gate to close or open, thereby closing or opening the wellhead, achieving the purpose of sealing and opening the well

The gate of the gate blowout preventer is divided into four types: fully sealed, semi sealed, variable diameter, and shear gate, which are used for well sealing under different conditions. A semi sealed gate can seal corresponding pipelines such as drill rods and oil pipes, and can suspend drilling tools if necessary. When there is no pipeline in the well, the fully sealed gate can completely seal the wellhead. In special circumstances, the shear gate can cut off the drilling tool. In addition, drilling fluid circulation and throttling well killing operations can be carried out at the flange outlet next to the casing

The annular preventer can be divided into conical annular preventer and spherical annular preventer according to the shape of its sealing rubber core. Its structure mainly consists of four parts: shell, top cover, rubber core, and piston

When tools are available for homework, the annular preventer can seal various annular spaces with rubber cores. When there are no tools in the well, the wellhead can be completely closed during drilling, coring, logging and other operations, as well as the annulus formed by the square drill pipe, coring equipment, cables and wires and the wellbore. When using pressure reducing and regulating valves, the drilling tool can be forcibly pulled out and lowered through the drill rod