WELL HEAD DEVICE FOR TUBING STRING RELEASE FROM WELL Russian patent published in 2010 - IPC E21B31/107 

FIELD: oil-and-gas industry.

SUBSTANCE: well head device for tubing string release from a well includes a damper, installed between a lift and vertical impulse generator. At that a damper performed as a vertical sealed cylinder with a piston, which internal cavity filled with gas, and the vertical impulse generator executed in a shape of few connected between each other hydro cylinders, inside of each located pistons with rods connected between each other. At that rods are void and hydraulically connect cylinders under piston space with each other. The under piston space executed with ability to interact with a pump, equipped with buffer, via distributor, containing from double chambered cylindrical case, which chambers connected with each other through a channel, and rotating with a drive wall, equipped with a cup, which periodically connected to the mentioned above channel.

EFFECT: design simplification and efficiency increase during tubing string release form a well, due to pulling upwards force increase.

2 cl, 2 dwg