1. Role 

In supporting the use of hydraulic control system, when a drill hole, closed to the annular space of different sizes; when no drill hole, totally closed wellhead. Here a coring, logging operations when the WBC, the drill pipe can be closed, coring tools, cable, wire rope, and other shaft formed annular space. In decompression Pressure Regulating Valve and buffer storage device support, through small study of 18 degrees without deduction welded drill pipe, forced from the drilling operations. 

2. The operating principle of annular BOP 

Ring BOP manipulated by hydraulic control system. The closure, the central high-pressure oil from Shell Oil closed lower part of the mouth cavity enter Detroit, the Pistons uplink promote Pistons conical extrusion plastic core. Because of the restrictions roof, plastic-not only pushed up to the wellhead centers until drill or completely closed wellhead, and realize its purposes. 

When the need for open wells, the hydraulic control valve control system, high pressure oil from the Shell I opened the top of the piston into the cavity to promote Detroit downlink, closed cavity pressure relief, the role of core-cone in the plastic extrusion pressure elimination of flexible plastic core force in itself gradually reposition and opened wellhead. 

3. Application requirements 

(1) in a drill hole when the blowout occurred, to use Central BOP control wellhead, but try not to be closed for a long time, a plastic core easily damaged, the no locking device. Non-exceptional circumstances, not using it closed empty wells. 

(2) using annular BOP for not killing from the drilling operations will take 18 degrees with the use of bottom hole slopes. Under a joint drill from slower speed, all the rubber drilling tool for hoop should all rip. 

(3) annular BOP remained closed, shut-in pressure in 5 Mpa following activities may be from top to bottom, bottom hole. But prohibit rotating drill. 

(4) use is strictly prohibited open annular BOP means to vent to hole pressure to prevent thorn Central plastic core.

(5) After the wells will each open-ice check whether against pegged bad plastic core. 

(6) Cementing, and stopping leaks, and other operations, to clean the inner cavity and maintain switching flexibility. 

(7) installation or removal of annular BOP, we must pay special attention to Central and steel ring gaskets trough, not crashing or scratches. 

(8) the purpose of entering and exiting after the drilling of each one should bring with them a drill test wells customs inspection plastic core effect. Substandard request should immediately replaced. 

(9) in accordance with the relevant standards, should regularly annular BOP to a wellhead pressure test. 

Detailed product parts