FIELD: mining.
SUBSTANCE: invention relates to devices intended for sealing the mouth of production and injection wells at successive lifting from the well of a two-lift arrangement of downhole equipment. Disclosed is a device for sealing at the wellhead of a two-lift arrangement of downhole equipment, comprising a preventer with a cast lower flange, which is tightly attached to the support flange of the wellhead equipment. Preventer is equipped with a replaceable ring, which is made connecting and sealing, with dimensions corresponding to the dimensions of the support flange of the wellhead equipment, on which the preventer is attached. Preventer is additionally equipped with a shut-off assembly containing a sub, a branch pipe and a ball valve. Preventer rams are made with possibility of sealing of shutoff assembly. Also, the preventer is equipped with a coil connected to the flange-pipe holder of the wellhead by means of a tight threaded connection. Device is equipped with two taps. At that, the first branch on one side is fixed in the hole for the long pipe string in the flange-pipe holder with a tight threaded connection, and on the other side the first branch is equipped with a ball valve. Ball valve is hydraulically connected to the storage tank through the first quick-release connection and the first flexible hose. Second branch on one side is connected by a tight threaded connection to the ball valve of the shut-off assembly, and on the other side the second branch is equipped with the second quick-release joint and the second flexible hose is hydraulically connected to the accumulation tank. Device is also equipped with a removable centralizer equipped with a radial groove for passage of a long pipe string and two recesses located at angle of 180° on external surface of removable centraliser for rigid fixation of removable centraliser by two stop screws in axial hole of preventer during lifting of pipes of long string. Width of the radial slot and the diameter of the through hole of the removable centralizer are selected depending on the diameter and the coupling of the pipe of the shut-off assembly.
EFFECT: enlarging functional capabilities and accelerating the process of tripping operations with a short pipe string.
1 cl, 4 dwg
