SET OF TUBE RAMS OF PREVENTER Russian patent published in 2020 - IPC E21B33/06 

FIELD: mining.

SUBSTANCE: invention relates to devices used in preventers intended for sealing of mouth during repair of steam-injection wells with inclined mouth at performance of lowering-lifting operations (OPO) with two string of pipes. Set of tube rams of preventer contains two central channels forming central channel for ram tube passage, each of which comprises front seal for tube and upper seal for top mirror of ram channel. At that, front seal from above and from below is reinforced by metal plates recessed into sealing material with through semicircular recesses, and in upper seal for connection with front seal provided at least two guide pins. Housing of each ram is made of a single-piece structure and has the shape of a parallelepiped with a chamfered rear face, in which a blind T-shaped slot is made, which is open from the lower edge of the ram for connection of the ram to the stock of the preventer drive. On the upper face of the body there is a groove shaped to a semicircle with a center shifted from the front to the rear faces, and a straight outer section facing the front face, in which the upper seal is located, in the front face of the body there is a blind groove with a lower, upper and side faces, which is connected to the groove on the upper face and serves for arrangement of the front seal having the shape of a rectangular parallelepiped. In slot in direction to rear face of ram housing there is a semicircular groove, center of radius of which is shifted outward from front face of ram housing by value S, and in the front face of the ram housing there is a through semicircular cutting out with diameter d under the pipe, the value of which is greater than the diameter of the sealed pipe, note here that its center coincides with axis of central through channel for pipe. On the front face of the body of the rams there are teeth and grooves for the tooth from the paired ram. Upper seal has a rectangular cross-section with a skewed upper trailing edge. Central through channel for pipes passing, formed by tube rams, exceeds diameter of pipe by thickness of metal plates of front seal. Tube rams form two central channels for sealed pipes of small d and large D diameters. In front edge of each ram there are two eccentrically arranged through semicircular recesses with diameters d₁ and D₁, values of which are greater than small d and large D diameters of sealed pipes. Centers of each semicircular recess are aligned with axes of through central channels for sealed tubes. Distance between nearest ends of semicircular recesses with diameters d₁ and D₁ makes it possible to make additional front face, wherein front and upper seals, upper and lower metal plates are equipped with two eccentrically arranged through semicircular recesses for sealed pipes of small d and large D diameters. For self-centering of rams when they are brought together on front face and additional front face of housing of one of rams in upper, middle and lower parts there are slots with internal threads, by means of which teeth are inserted into grooves. On the front face and the additional front face of the housing of the other ram, as well as in its upper, middle and lower parts, mating slots are made for the matching teeth of the pair ram, wherein the front part of teeth protruding beyond the front face and the additional face of the ram housing is made in the form of a cone surface of length l converging to the front edge in ratio of 2.2:1, wherein the grooves in the mating housing of the ram of length L are made in the form of a surface of the cone contracting inwards at ratio of 2:1, wherein the grooves and the teeth have a circular cross-section. Front and top seals are made of heat-resistant rubber.

EFFECT: set of tube rams of preventer at pipe sealing on the wellhead of inclined steam-injection well allows improving reliability of pipes sealing, improving accuracy of alignment of rams with each other, enlarging technological capabilities of application, providing tightness in case of steam emission at temperature up to plus 300 °C.

1 cl, 8 dwg