CIRCULATING VALVE Russian patent published in 2013 - IPC E21B34/06 

FIELD: oil and gas industry.

SUBSTANCE: valve consists of a detachable housing with a seat on its end face, a spring-loaded end valve, and an annular piston with a spool valve. In addition, the valve is equipped with a hydraulic cylinder with an annular piston provided with a cup and a bottom, in which a shutter is installed so that an annular gap with a shaft passed through an axial channel of the detachable housing can be formed. The annular gap is connected via a drain channel in the bottom body to the well cavity. The cavity of the hydraulic cylinder under the annular piston is connected via channel to the axial channel of the shaft. End valve is installed on the seat made on inside surface of upper part of the detachable housing. A spool valve is provided with an expanding cone with a longitudinal slot on outside surface and is installed so that it can interact with the cup of the annular piston of the hydraulic cylinder. At that, the annular chamber above the annular piston is hydraulically connected through a radial hole to the axial channel of the shaft, and through a hole in the body of the detachable housing under the end valve to intertube space of the well above the device installation place.

EFFECT: possibility of forming hydrodynamic connection between intertube space and axial channel of a production tubing string after formation fluid supply via the production tubing string to the well head is completed.

6 dwg