PREVENTER FOR A WELL WITH TWO-ROW STRING AND INCLINED MOUTH Russian patent published in 2020 - IPC E21B33/06 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to sealing equipment of wellheads of oil and gas wells during their operation and repair. Preventer for a well with double-row string and inclined mouth contains upper and lower flanges, rigidly connected to housing equipped with vertical circular axial channel, symmetrically relative to axial channel there are two side horizontal channels, longitudinal axes of which are located perpendicular to axis of vertical channel. In the first horizontal channels with possibility of longitudinal movement there installed are ram blocks, in which there are tube rams equipped with elastic seals, and manual drives of rams control, which include driving rods of rams, having threaded connections for interaction with covers screwed into housing. At that cavities of housings of ram blocks in cross section have rectangular shape, and elastic seals are arranged in slots made in tube rams. In the second horizontal channels located in the upper flange, in the sealed version from the outside, there are screwed side screw supports, interacting with the sliding sliders, which are equipped with key slots, and upper flange is equipped with keys, installed in key slots of sliding slides, having the possibility of longitudinal movement within key slots. Connecting and sealing sizes of the preventer lower flange are made corresponding to that of the wellhead reinforcement flange on which the preventer is attached. Elastic seals are made of heat-resistant rubber. Ram blocks with tube rams in the first horizontal channels are equipped with two semi-ring recesses with slots, note here that sealing elements made up of semi-rings of heat-resistant elastic seals are installed and fixed in grooves of semi-ring recesses of tube rams. In the second horizontal channels there are sliding slides with additional tube rams equipped with two semi-ring recesses, in which aligning elements made in the form of semi-rings are installed and fixed. A bushing equipped with two through vertical centering channels is installed from the bottom into the axial channel of the preventer. At that, the bushing can be fixed against vertical and rotary movement relative to the preventer body. At that, central axes of semi-ring recesses of tube rams and central axes of semi-ring samples of additional pipe rams, as well as central axes of bushing centering channels are located relative to central axis of axial channel of housing eccentrically on different sides from central axis of axial channel of housing at angle of 180° between each other and at distances providing centering of pipe strings relative to axial channel of preventer body in inclined well and sealing of pipe string with couplings and string of flexible pipes at occurrence of oil, gas and water ingress. Diameters of centering elements of additional tube rams and diameters of bushing centering channels are made for external diameters of two columns, and diameters of centering elements of additional pipe rams and centering channels located under each other, are equal to each other. Ram blocks are arranged in horizontal channels with the possibility of simultaneous performance of lifting-down operations of two columns: a pipe string with couplings and a flexible pipe string without their interaction at the mouth of the inclined well.

EFFECT: enlarging technological capabilities of the device, improving the quality of sealing of pipe strings, improving safety of work at the mouth of inclined wells, reducing duration of round-trip operations.

1 cl, 5 dwg