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 vertical impulse generator and a damper, installed between a lift and the vertical impulse generator. At that the damper executed as a vertical sealed cylinder with a piston, which internal cavity under the piston filled with gas, and the generator executed as a tube case, consisting from serially connected power cylinders, inside of which located pistons with rods connected to each other. At that rods executed as void and hydraulically connect cylinders under piston cavities between each other. Under cylinder cavity of one of the rods connected via distributor and a safety valve with a piston non-valved pump, equipped with a buffer tank. The distributor consists of a cylindrical case with two chambers, separated with a wall, equipped with straight valve for liquid supply from a pump and a return valve for liquid collection from power cylinders, at that the return valve string press load is bigger then the straight valve string press load. The safety valve located in a bypass fitting lateral channel between the distributor and the pump, and executed with ability of the fitting connection with the buffer tank.

EFFECT: simple design and the tubing string release from a well efficiency increase.

1 dwg