The annular BOP (English: Annular Blowout Preventer) are often equipped with a large gate of ram blowout preventer, the operation will form a sealed annular space between the string and well bore, in the well pipe string under you, also can complete the sealing well alone, but the use of several., and does not allow the use of long-term shut.
One, the annular BOP function is what?
⑴ as well a pipe column, can seal the tube column and wellhead annular space formed by a rubber core;
The empty wells can be closed wellhead;
In the process of drilling and milling, grinding sleeve, logging and fishing downhole falling objects, if overflow, blowout, the forming tool and wellhead seal Kelly, cable, wire rope and handling of accidents in space;
In the vacuum pressure regulating valve or small accumulator with thin buckle, no forced snubbing operation of pipe column joints of 18 °;
⑸ met serious overflow or blowout, used in conjunction with the blowout preventer and the manifold to achieve soft shut in.
Two, with the annular BOP drilling tools should pay attention to what have shut?
(1) are only allowed to play 18 degrees without thin buckle butt welded drill pipe.
(2) in the drilling process, there is a small amount of leakage between the rubber core and the drill pipe, not only is allowed, but it is necessary. A small amount of leakage of drilling fluid can lubrication, cooling the rubber core, improve the service life of the rubber core. When necessary, can be lubricated rubber core in the rubber core top lubricating fluid.
(3) tripping speed must be slow, especially when a joint.