FIELD: oil production.
SUBSTANCE: means for sealing the mouth of oil and gas wells. The preventer with a coil contains a preventer with a cast bottom flange, which is hermetically attached to the wellhead fitting support flange using studs and nuts. The support flange of the wellhead fitting is equipped with a pipe support. The preventer is equipped with a coil from below, consisting of the lower and upper flanges connected to each other by a guide pipe using threaded connections. The coil flanges are made with eccentricity between the central axes of the upper and lower flanges. The inner diameter of the guide pipe is 20 mm larger than the maximum outer diameter of the pipe string or downhole equipment lowered into the well. The height of the guide pipe provides a distance between the lower and upper flanges of the coil greater than the length of the studs. The upper flange of the coil is made with a connecting and sealing size corresponding to the lower flange of the preventer. The lower flange of the coil is made with a connecting and sealing size corresponding to the support flange of the wellhead fitting. To implement the method for installing the preventer, the equipment and the preventer are assembled using studs and nuts. A pipe support is installed in the mounting flange of the wellhead fitting. Between the lower flange of the preventer and the mounting flange of the wellhead fitting, a coil is hermetically fixed, equipped with an eccentrically guiding pipe. At the end of the tripping operations with the first row of the pipe string, the fastening of the lower flange with the mounting flange of the wellhead fitting is unscrewed and the coil together with the preventer on the mounting flange is rotated by 180° and the lower flange of the coil is fixed on the mounting flange with studs and nuts.
EFFECT: reduction of the duration of successive landing of two pipe strings by eliminating the dismantling of the wellhead fittings and the dismantling of the preventer.
2 cl, 2 dwg
