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

FIELD: mining.

SUBSTANCE: invention relates to circulation valves of drill string. Valve includes tubular housing, slide bushing located inside housing, seat located in central channel of slide bushing, guide ring, located in inlet part of housing, spring, pressing slide bushing against guide ring. Through inner cavities of housing, guide ring, seat, and slide bushing, pump supply of fluid medium is performed. Valve also includes two circulation ports fixed in case with flow openings, ports are closed by slide bushing in inactive mode, whereat fluid is fed with pump via drill column, and are open to allow communication with inner space of drill string, when circulating valve is in active mode. Valve comprises also disposable activation ball, made with possibility of deformation and passing through seat during motion of fluid via drill column, and also two locking balls released one after another, interacting with circulation ports for blocking fluid medium flow through said circulation ports. Valve also comprises threaded adapter secured to housing with device for catching balls inside, while fluid flows through seat. Circulation valve comprises sleeve, located inside tubular housing. Slide bushing therein is made solid, arranged to translate inside sleeve, and is equipped with own external seals in contact with inner surface of sleeve. At that, in inactive mode at which circulation ports are closed with slide bushing, pump feed of fluid via drill column is performed. Ports are located downstream from seat, own outer seal of slide bushing are located on opposite sides relative to circulation ports, and in active mode, wherein circulation ports are open to allow communication with inner space of drill string, upstream edge of slide bushing is located downstream of circulation ports. Sleeve is made with through side holes, each circulation port has edge extending inward from inner surface of body. Sleeve is fixed with each through side hole relative to edge of circulation port directed inward, and inner profiles of inlet flow parts of circulation ports converging towards outer surface of tubular housing.

EFFECT: technical result consists in improvement of service life and reliability of valve.

4 cl, 7 dwg