CIRCULATION VALVE OF A DRILL STRING Russian patent published in 2022 - IPC E21B21/10 

FIELD: petroleum industry.

SUBSTANCE: invention relates to the petroleum and gas industry, in particular, to circulation valves of a drill string allowing for multiple switching of the fluid flow. The apparatus comprises a tubular body, a spool sleeve with external holes and a central channel, wherein a seat is placed. The spool sleeve is fastened with a shank, installed inside the body, comprises a compressing spring. The apparatus comprises in the body two circulation ports with flow holes, covered with the spool sleeve in the inactive mode, during pump feeding through the drill string, and open in the active mode, a drop activation ball configured to pass through the seat in the central channel of the sleeve when a fluid is moving, and two locking balls interacting with the circulation ports in order to block the fluid flow. An output sub with a ball-catching apparatus placed therein is fastened with the body, an input sub with a central channel is located upstream, the profile at the output of the central channel of the input sub is made as a channel with a critical section. The upstream edge of the sleeve and the downstream edge of the input sub are made in the form of adjacent conical surfaces, the surface of the upstream edge of the sleeve is made in the form of an inner conical surface, the surface of the downstream edge of the lower sub is made in the form of an outer conical surface, the vertices of the cones are pointed in the direction of the seat.

EFFECT: resource and reliability are increased, pumping of all types of mudding materials is ensured, tightness of the locking balls is increased, sticking of the spool sleeve is prevented.

5 cl, 8 dwg