Circular Anti Spray Device

Circular Anti Spray Device

The annular blowout preventer is operated by a hydraulic control system. When closed, high-pressure oil enters the lower closing chamber of the piston from the oil port in the middle of the housing, pushing the piston upward and squeezing the rubber core on the piston cone surface. Due to the limitation of the top cover, the rubber core cannot ascend and can only be squeezed towards the center of the wellhead until it tightly holds the drilling tool or fully seals the wellhead, achieving its purpose of sealing the well.
When it is necessary to open the well, operate the directional valve of the hydraulic control system to allow high-pressure oil to enter the opening chamber on the upper part of the piston from the oil port on the housing, push the piston down, close the chamber to release pressure, eliminate the squeezing force acting on the conical surface of the rubber core, and gradually reset the rubber core under its own elastic force, opening the wellhead.

Usage Requirements
When there are drilling tools in the well and a blowout occurs, a circular blowout preventer can be used to control the wellhead first, but it is best not to seal it for a long time. Firstly, the rubber core is prone to damage, and secondly, there is no locking device. Unless under special circumstances, it is not necessary to seal the empty well.
When using a circular blowout preventer for non pressure well drilling operations, it is necessary to use drilling tools with an 18 degree slope. When passing through the joint, the drilling speed should be slow, and all rubber clamps on the drilling tools should be removed completely.
When the annular blowout preventer is in the closed state and the shut in pressure is below 5MPa, the drilling tool can be moved up and down, but rotation of the drilling tool is prohibited.
It is strictly prohibited to use the method of opening the annular blowout preventer to release the pressure inside the well, in order to prevent damage to the rubber core.
After each well opening, it is necessary to check whether it is fully open to prevent damage to the rubber core.
After cementing, plugging and other operations, the inner cavity should be flushed clean and the switch should be kept flexible.
When installing or disassembling the annular preventer, special attention must be paid to the sealing gasket ring and steel ring groove, and it is not allowed to damage or scratch them.
After entering the target layer, the drilling tool should be used to test and shut in the well with each trip to check the sealing effect of the rubber core. If it does not meet the requirements, it should be replaced immediately.
According to relevant standards, pressure tests should be conducted regularly on the wellhead annular preventer.

Main Technical Parameters