WELL HEAD RETURN VALVE OF OIL WELL Russian patent published in 2009 - IPC E21B34/02 E21B33/03 

FIELD: oil-and-gas production.

SUBSTANCE: invention related to oil-and-gas production, particularly to devices for maintain a regular regime of production well operation, for instance oil wells or oil-and-gas wells, or oil-and gas condensate wells and others, characterised gas presents in hole clearance. It includes hollow case, equipped with inlet connection for main component supply - stratum fluid and inlet connection for dropped component supply, also outlet connection for discharge of the main and dropped components. In the return valve case installed internal cup shaped block, which has canal in its lateral wall for annular gas discharge, located angularly to stratum fluid flow vector with an ability to wash internal surface of the cap lateral wall with the fluid.

EFFECT: maintain a regular regime of production well operation due to wellhead assembly reliability increase, particularly because of return valve ability to wash internal surface of the cap lateral wall with the warm fluid, optimal thermal regime in return valve zone in case of bad external conditions of the wellhead.

17 cl, 6 dwg