RAM-TYPE BLOWOUT PREVENTER FOR WELLS WITH TWO-ROW STRING PIPE 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 in order to ensure safety, prevention and elimination of oil, gas and water ingresses (OGWI), including at wells with inclined mouth of two-row pipe string, protection of entrails and environment. Ram-type blowout preventer for borehole with two-row string comprises upper and lower flanges rigidly connected to housing, housing is equipped with a vertical circular axial channel, relative to the axial channel there are symmetrically arranged side horizontal channels, longitudinal axis of the side horizontal channels are located perpendicular to the axis of the vertical channel, in the first horizontal channels made in the housing with the possibility of longitudinal movement, there are installed ram blocks, in which the pipe rams are installed, equipped with elastic seals, and manual control drives of rams, which include drive rods of rams, having threaded connections for interaction with covers screwed into housing, at that, the cavities of the housing of the ram blocks in the cross section have a rectangular shape, and the elastic seals are placed in slots made in the tube rams. Upper part of the axial channel of the housing is equipped with a conical mounting surface narrowing downwards for installation of a replaceable sealing bushing. In upper flange second horizontal channels are made and have round shape in cross section. Outside, side screw stops are screwed into the horizontal channels of the upper flange in a sealed design, side screw stops interact with draw-out cylindrical sliders arranged in the horizontal channel; at that, draw-out sliders are equipped with key and shaped slots. Upper flange is equipped with keys installed in key slots of draw-out sliders, having the possibility of radial movement within the limits of key slots and rigid fixation of replaceable sealing bushing in conical mounting surface of housing by shaped slots of sliders. In preventer ram blocks there are tube rams provided with elastic seals on the basis of maximum outer diameter of pipe string of double row string, and for sealing of pipe string with minimum outer diameter of two-row pipe string in its assembly at wellhead there installed is emergency branch pipe with maximum outer diameter of pipe string equal to maximum outer diameter of pipe string from two-row string of pipes. Emergency branch pipe is equipped at the top with a ball valve, and at the bottom – with a reducer equipped with a thread from below, corresponding to thread of a pipe string coupling with minimum outer diameter of a two-row pipe string. Elastic seals are made of heat-resistant rubber, operating in temperature range from minus 65 to plus 300 °C.

EFFECT: proposed ram-type blowout preventer for well with two-row string has simple design; compact and easy to use; versatility during operation with two-row pipe string; accelerated installation at the well head of inclined wells; high efficiency in operation; high safety of work at wellhead of inclined wells in case of OGWI occurrence; high-quality air-tightness in case of steam release at temperature up to plus 300 °C.

1 cl, 4 dwg