Circulation valve Russian patent published in 2021 - IPC E21B21/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to a device for drilling oil and gas wells, namely, circulation valves. The device contains a housing, two circulation ports with seals fixed in the housing, a spring that presses the piston, activation and deactivation balls, a sub with a device for catching balls, a sleeve fixed inside the housing by circulation ports, a piston with radial holes and a central channel. Inside the piston there is a seat having an internal sealing diameter for a tight fit of the activation ball, which is less than the diameter of the activation ball by 0.01...1%. Downstream of the drilling fluid relative to the sealing diameter, the seat has internal protrusions to hold the activation ball, the total area of the internal protrusions of the seat in the cross section is 1...15% of the cross-sectional area of the activation ball, the activation ball has a hardness of 95 Shore A to 90 Shore D. The seals of the circulation ports on the piston side are hard-mounted in the inner grooves of the sleeve on both sides relative to the circulation ports. The piston support and centering rings are installed in the inner grooves of the sleeve. The sleeve is made of corrosion-resistant material.

EFFECT: invention extends the service life and improves operation reliability, improves wellbore cleaning, provides ability to restore the drilling fluid parameters and to replace process fluids.

2 cl, 4 dwg