Diverter system and blowout preventer

A system adapted for alternative use as a blowout preventer or a diverter, comprising

• a blowout preventer having a resilient packing means and having a closing port and an opening port by which connection of a source of pressurized hydraulic control fluid to the closing port closes the blowout preventer and connection of a source of pressurized hydraulic fluid to the opening port opens the blowout preventer, the blowout preventer when open having a vertical flow path for drilling fluid returns,
• a diverter spool means having a vertical flow path and disposed in series with and below the blowout preventer, the spool means having
• a diverter housing having an outlet passage provided in its wall,
• a diverter piston having an annular wall and disposed within the housing,
• a lower control port in said housing by which connection of a source of pressurized hydraulic fluid to the lower port raises said piston from a lower position to an upper position and an upper control port by which connection of a source of pressurized hydraulic fluid to the upper port lowers said piston from an upper position to a lower position in said housing,
• said outlet passage in said housing wall being closed off by the annular wall of the piston when said piston is in said lower position and being open to the interior of the housing when in said upper position, means for alternatively connecting
• a vent line or a closure means to said outlet passage in the wall of the diverter housing,
• hydraulic conduit means for connecting the upper control port of said diverter piston with the closing port of the blowout preventer,
• a reservoir of hydraulic control fluid disposed in the diverter housing above the diverter piston when the piston is in the lower position, and
• hydraulic circuit means for connecting a source of pressurized hydraulic control fluid to said lower control port of said diverter housing, operably raising said diverter piston from its lower position and opening said outlet passage in the wall of the diverter housing while forcing hydraulic control fluid from said reservoir to said closing port of the blowout preventer via said hydraulic conduit means and operably closing said blowout preventer.

A diverter spool adapted for use with a drilling rig annulus sealing means, the annulus sealing means having a closing port by which application of pressurized hydraulic fluid to the closing port closes the annulus sealing means, the diverter spool comprising,

• a diverter housing having an outlet passage provided in its wall,
• means for connecting the diverter housing below the annulus sealing means,
• a diverter piston having an annular wall and disposed within the housing,
• a lower control port in said housing by which connection of a source of pressurized hydraulic fluid to the lower port raises said piston from a lower position to an upper position and an upper control port by which connection of a source of pressurized hydraulic fluid to the upper port lowers said piston from an upper position to a lower position in said housing, and
• said outlet passage in said housing wall being closed off by the annular wall of the piston when said piston is in said lower position and being open to the interior of the housing when said piston is raised from said lower position.