Blowout preventer

A blowout preventer, adapted to be incorporated in a drill string, said blowout preventer comprising:

• a tubular body having a central through-bore aligned with a bore of the drill string and at least one passageway having a fluid inlet and a fluid outlet, the at least one passageway extending substantially parallel with the central through-bore;
• a radially and circumferentially expandable packer means being shiftable between a retracted, inactive position for permitting fluidflow in an annulus defined between the drill string and a wall of a wellbore and a released, expanded position for sealing with the wall of the wellbore;
• and
• a latching and releasing means being moveable between a latched position for preventing said packer means from expanding and an unlatched position for releasing said packer means and permitting said packer means to expand into the released, expanded position, wherein
• at least one of said packer means and said latching and releasing means is configured and positioned relative to the fluid outlet such that when said packer means is in the retracted, inactive position or said latching and releasing means is in the latched position, the fluid inlet is covered and closed, and when said packer means is in the released, expanded position, the fluid inlet is uncovered and opened.