PREVENTER Russian patent published in 2005 - IPC

FIELD: equipment used for underground oil and gas well repair, for sealing well head in emergency and during long operation interruption.

SUBSTANCE: preventer has body with axial channel adapted for passing pipes with processing facilities into well, pipe rams with piston-like hydraulic drive installed in side lids and blind rams with piston-like hydraulic drive mounted in side lids. Preventer also has hydraulic cylinders connected in pairs through communication channels adapted to supply working liquid. Each channel communicating hydraulic cylinder with working liquid injection pipeline is provided with shut-off valve. One part of shut-off valve is arranged in body, another part is installed in side lid. When side lid is attached to body bypass channel is installed in opened position. When side lid is removed from the body for ram replacement bypass valve may close channel, which communicates hydraulic cylinder with working liquid injection pipeline to provide air-tightness of hydraulic drive system to prevent liquid from leaking from hydraulic cylinder interior.

EFFECT: possibility to retain air-tightness of channel connection with hydraulic cylinder interior during side lid demounting.

6 dwg