First, what annular BOP function is?

⑴ When there is the well string, the string can be closed with a glue core wellhead annular space formed;

⑵ can empty the whole time well wellhead seal;

⑶ during drilling and milling, grinding sets, well logging and salvage process falling objects, if an overflow occurs, when a blowout can be sealed kelly, cable, wire rope and wellhead handling tools and the space formed by the accident;

⑷ pressure regulator or in cooperation with a small accumulator, capable of 18 ° unscrewed butt column joints under force from the job;

When ⑸ case of severe flooding or blowout for mating ram preventer and choke manifold soft shut.

Second, when using the annular BOP shut tripping drill should pay attention to what?

(1) only allows thin starting at 18 degrees without deduction welded drill pipe joints.

(2) in the tripping process, a small amount of leakage between the plastic core and the drill is not only permissible but necessary. The drilling fluid may leak a small amount of lubrication, cooling rubber core, improve the life of rubber core. If necessary, add lubricating fluid to lubricate the rubber core in the top of the plastic core.

(3) tripping speed must be slow, especially when crossing the joint.