DEVICE FOR STOPPING FLUID FLOW IN THE WELL

FIELD: oil and gas extractive industry. ^ SUBSTANCE: device has packer, lower cutting valve, pressure transfer assembly with sphere valve, cutting valve control mechanism and a plunger. Cutting valve control mechanism has cylindrical body coaxially mounted with plunger with serially repeating on its inner surface grooves of varied depth, reciprocal spring and bushings with projections for interaction with body grooves. Pressure transfer assembly is made in form of piston with axial aperture and plunger fixed to it. It passes through said aperture and is made hollow with recessed apertures in lower end and bypass port between pressure transfer assembly and the piston. Cutting valve is cinematically connected to plunger. Plunger is in rigid connection to cutting valve control mechanism. ^ EFFECT: possible plugging of well during operation in case of emergency, maintenance and other special conditions. ^ 1 dwg