[the annular BOP]

1, role

In supporting the use of hydraulic control system, while drill tools in hole, annular space can be closed with different size; when there is no drill hole, can fully closed wellhead. The coring, logging operation of blowout, Kelly, sealed coring tool, cable, wire rope and wellbore annulus formed. In the vacuum pressure regulating valve and buffer storage device coordination, through 18 degrees without thin buckle welded drill pipe, forcibly tripping.

2, the annular BOP principle

By the hydraulic control system to operate the annular bop. When closed, the high pressure oil from the oil inlet. The middle part of the lower part of the piston closed cavity, the piston is pushed up, the piston cone extruding rubber core. Because the top limit, the rubber core can not only pushed to uplink well center, until the

Hold the drill or closed wellhead, well sealing to achieve. When the need to open well, hydraulic control system of valve, the high pressure oil cavity shell oil into the mouth opening from the upper part of the piston, pushes the piston down, closed cavity pressure relief, role in the rubber core cone extrusion pressure to eliminate, rubber core role in itself gradually reset elastic force, open the mouth.

3, use requirements

(1) a drilling tool in the well blowout, can first use of annular BOP control well, but try not to be closed for a long time, a rubber core is easy to damage, two without locking device. Non special circumstances, it is not closed well.

(2) were not snubbing operation with the annular BOP, must use the tool with 18 degree slope. The drilling speed will slow over joints, rubber cover all tools should be removed.

(3) the annular BOP is closed, shut in pressure below 5MPa, can move up and down hole, but no rotary drill.

(4) is strictly prohibited for open annular BOP to vent to the pressure in the well, to stab the bad rubber core.

(5) each must check whether the open hole, in order to prevent the hanging bad rubber core.

(6) cementing, plugging operation, will wash clean, keep the switch flexible cavity.

(7) to install or remove the annular BOP, must pay special attention to seal ring and ring groove, not allowed to damage or scratch.

(8) into the objective layer, each round trip, with drilling test Kansai Ichiji, check the rubber core plugging effect. Not meeting the requirements, should be replaced immediately.

(9) according to the relevant standards, should be regularly preventer wellhead annular plates for pressure test.