DRILL STRING CIRCULATION VALVE Russian patent published in 2019 - IPC E21B34/14 E21B21/10 

FIELD: soil or rocks drilling.

SUBSTANCE: invention relates to the drill column circulation valves. Valve includes a tubular body, housed inside the body and having a seat spool bushing, made in the spool bushing central channel, mounted in the body input part guide ring, pressing the spool bushing to the guide ring spring, through the body internal cavities and the spool bushing seats the fluid pumping is carried out, and also contains fixed in the body two circulating ports with flow holes, in the inactive mode the circulation ports are closed by a spool bushing, during which the fluid pumping through the drill string is carried out, and are open and provide communication with the drill string internal space, when the circulation valve is in active mode, and also contains a droppable activation ball, made with possibility of deformation and passage through the spool bushing seat during the fluid movement along the drill string, and also contains two locking balls, droppable one after the other, interacting with circulation ports for the fluid flow blocking through the said circulation ports, and also contains fastened to the body threaded sub with located inside it the balls trapping device that have passed with the fluid flow through the spool bushing seat, and also contains a sleeve, located inside the tubular body, the spool bushing is made solid, placed with the possibility of longitudinal movement inside the sleeve and provided with seals in contact with the sleeve inner surface, at that in the inactive mode, whereby the circulation ports are closed by the spool bushing and fluid pumping through the drill string is performed, the said circulation ports are located downstream of the seat, and the spool bushing seals are located on the circulation ports opposite sides, at that in the active mode, in which the circulation ports are open and provide communication with the drill string internal space, spool bushing upstream edge is located downstream of the circulation ports, at that, the sleeve is made with through side openings, each circulation port is made with an edge projecting inward from the body inner surface, and the sleeve is fixed by each through side opening with respect to the edge of inward directed circulation port. At that, the spool bushing is made with increased length of its input cylindrical part located between its upstream seal, in contact with the sleeve inner surface, and the spool bushing upstream end, at that, located between its upstream seal and upstream end the said spool bushing input cylindrical part minimum length, is equal to the distance between the spool bushing seals located on the circulation ports in the inactive mode opposite sides, in which the circulation ports are closed by the spool bushing and the fluid pumping through the drill string is performed, and upon reaching contact with the droppable activation ball spool bushing seat, made with the possibility of deformation and passage through the spool bushing seat during the fluid flowing along the drill string, spool bushing is made with possibility of movement together with the activation ball, compressing the spring, thus, that in the position of the circulation ports flow ports overlapping with the spool bushing seal spool bushing inlet cylindrical part increased length in contact from the sleeve inner surface are located, each downstream from the circulation ports flow ports.

EFFECT: technical result consists in increase in the circulation valve service life and reliability.

1 cl, 8 dwg