DOUBLE ROW PIPE STRING BOREHOLE PREVENTER Russian patent published in 2023 - IPC E21B33/06 

FIELD: oil and gas wells wellhead sealing equipment.

SUBSTANCE: invention relates to oil and gas wells wellhead sealing equipment, in particular to double row pipe string borehole preventer during operation and repair for providing safety, preventing and eliminating oil and gas leakages, protecting subsoil and the environment. Preventer contains upper and lower flanges rigidly connected to the body with a vertical circular axial channel. The upper and lower rows of lateral horizontal channels are symmetrically arranged in the body relative to the axial channel. Each of the lateral horizontal channels contains ram units with pipe rams equipped with elastic seals and rams manual actuators with rams actuating rods that have threaded joints for engagement with covers screwed into the body. The ram units body cavities are rectangular in cross-section and the elastic seals are installed in the pipe rams slots. Ram units of upper lateral horizontal channels contain pipe rams with elastic gaskets for sealing tubing strings of smaller outside diameter, at the upper end of which a ball valve is installed on wellhead in closed position. The lower lateral horizontal channels ram units contain pipe rams with elastic gaskets to seal the pipe string of a larger external diameter, at the upper end of which a ball valve is installed on the wellhead in the closed position. The ram units of the upper lateral horizontal channels contain semi-ring slots formnig a closed ring slots located eccentrically to the blowout preventer axial channel housing axis. The rams installed in the ram unit of upper lateral horizontal channels have different lengths, as well as different lengths of the upper slots actuating mechanism. The preventer is fixed on a wellhead flange and is designed for installing below the preventer in a wellhead flange with two eccentrically located vertical holes of larger and smaller diameters for securing upper ends of downhole tubing strings of larger and smaller outside diameters. The pipe holder outer diameter is smaller than the preventer body vertical axial channel.

EFFECT: invention provides for expanding the preventer functionality, sequentially lowering and raising two pipe strings of different diameters with downhole equipment without removing the preventer from the wellhead, blocking the pipe string inner cavity in case of oil and gas leakage and reducing the time for assembling and disassembling the preventer at the wellhead.

1 cl, 5 dwg