CIRCULATING HEAD Russian patent published in 2019 - IPC E21B33/35 E21B34/04 E21B21/12 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and is intended for underwater production of hydrocarbons in access system to well, operations of well servicing with application of self-elevating floating drilling rig, semi-submersible drilling rig, drilling vessels or stationary platforms. Circulation head comprises circulating head piping system, vertical production shaft, killing and throttling line directed perpendicular to vertical production shaft, killing and throttling line damper, pressure sensor, gate valve opening, double shutoff valve. Double shutoff valve is installed in killing and throttling line and comprises first needle valve, second needle valve and third needle valve. First and second needle valves are installed in series, and the third needle valve is installed perpendicular to the first needle valve and the second needle valve between them. On one side the pressure gauge is connected to the double shutoff valve, and on the other side – to the signal transmission line from the pressure sensor. Filter is connected to the double shut-off valve via the third needle valve. Docking plate unites valve opening line with killing and throttling line and signal transmission line from pressure sensor. Fourth needle valve and the check valve are serially installed in the line of opening of the killing line valve in the direction from the killing line gate valve to the docking plate.

EFFECT: simplification of equipment design for well flushing procedures, well completion and tests.

4 cl, 1 dwg