CIRCULATION VALVE OF DRILL COLUMN Russian patent published in 2019 - IPC E21B21/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to devices for drilling oil and gas wells, namely to the circulating valves of the drill string. Device comprises a tubular body, a spool bushing inside the body, having a seat in the central channel, a guide ring in the inlet part of the body, a spring which presses the slide sleeve to the guide ring. Two circulation ports with feed ports are closed by a spool bushing in inactive mode, which pumps the fluid through the drill string and opens and provides communication with the inner space of the drill string in active mode. Resettable activation ball is made with the possibility of deformation and passing through the saddle as the fluid moves along the drill string. Two locking balls, discharged one after the other, interact with the circulation ports to block the flow of fluid. Sleeve is located inside the housing, the spool sleeve is placed with the possibility of longitudinal movement inside the sleeve and provided with upper and lower flow seals in contact with the inner surface of the sleeve. Upstream edge of the sleeve is located downstream of the ports. Sleeve is made with through side holes. Each port is made with a protruding inward from the inner surface of the case edge. Sleeve contains a threaded sub fastened to the housing with a device for trapping balls located inside it. Device comprises an annular piston located coaxially between the spool sleeve and the sleeve, having upper and lower ends, upper and lower holes, and an internal thread between them. Upstream end of the piston is made with an annular depression adjacent to the upstream opening. Downstream part of the piston is made with an annular groove on the outer surface with the ability to accommodate the downstream seal in contact with the inner surface of the sleeve. External thread is made in the middle part of the sleeve, the first and second cylindrical belts are made upstream of the thread with the formation of an annular protrusion. Piston and bushing are threaded for contact. Upstream end of the piston, the annular depression at the end of the piston, the second cylindrical belt of the slide sleeve, the end of the sleeve and the annular groove at the end of the sleeve form an annular chamber. Upstream seal is made in the form of an elastomer cuff in the form of a T-shaped cross section. T-shaped shelf cuff mounted on the second cylindrical belt of the spool bushing, located upstream from the first belt. Downstream edge of the cuff is located in an annular cavity at the end of the piston. Upstream edge of the cuff is located in the annular groove at the end of the sleeve. Sleeve and the piston are made with the possibility of longitudinal movement inside the sleeve together with the ball in such a way that in the position of overlap of the flow ports of the ports by the inlet cylindrical part of the spool sleeve, the upstream seal is located downstream from the flow ports of the circulation ports and contacts the inner surface of the sleeve.

EFFECT: increased resource and reliability of the circulation valve.

1 cl, 9 dwg