CIRCULATION VALVE OF DRILL COLUMN Russian patent published in 2016 - IPC E21B21/10 E21B34/14 

FIELD: mining.

SUBSTANCE: invention relates to circulation valves of the drill column. Valve includes a tubular body with threads on its ends, a valve bushing with side through-holes arranged inside the body, a seat arranged inside the valve bushing, a guide ring arranged in the inlet part of the body, a spring pressing the valve bushing to the guide ring. Pump feed of fluid medium is realised via inner cavities of the body, the guide ring, the seat and the valve bushing. Valve also includes two fixed in the body circulation ports with flow ports, while the ports are arranged upstream of the seat, are closed with the valve bushing in inactive mode, during which there is realised mechanical supply of liquid medium through the drill column, and are open to allow communication with the inner space of the drill string, when the circulation valve is in active mode. Valve also comprises a drop activation ball, made with a possibility of deformation and passage through the narrowing section of the seat flow area during passage of liquid flow via the drill column, as well as two locking balls dropped one after another, interacting with circulation ports for blocking the liquid medium flow through the said circulation ports. Valve also comprises a secured to the the body threaded adapter with a located inside it device for catching the balls that passed through the narrowing section of the seat flow area. At that, the valve comprises a sleeve, arranged inside the tubular body and equipped with own external seals being in contact with the body inner surface. Valve bushing is installed with a possibility of sliding inside the sleeve and is equipped with own seals relative to the sleeve inner surface. Sleeve is made with through side holes, and every circulation port has an extending inward from the inner surface of the body edge, while the sleeve is fixed by every through side hole relative to the appropriate edge directed inside the circulation port. At that, the valve bushing is provided with an annular channel on its outer surface, which is connected with it through side holes, and the inner profile of every through side hole of the valve bushing is made convergent in the direction of the annular channel on its outer surface.

EFFECT: increased service life and reliability of the valve.

4 cl, 7 dwg