Patent ID: 8573557

Claim:
A ram blowout preventer for bidirectionally sealing a well, the ram blowout preventer comprising: a body having a cavity with a recess; a ram block configured to move between a closed position and an open position inside the cavity; a top seat disposed in the recess and configured to seal the well when in contact with the ram block; a movable lock ring extending inside a groove of the body and a corresponding groove of the top seat, a width of the groove of the body being different than a width of the groove of the top seat by at least a predetermined value, the movable lock ring being configured to move inside one of the grooves, along a direction substantially parallel to the well between a first seat position and a second seat position; a first seal positioned between the top seat and the body, the first seal being configured to contact the body and the top seat; and a second seal positioned between the ram block and the top seat, the second seal being configured to contact the ram block and the top seat when the ram block is in the closed position, wherein a distance from a centerline of the well to the first seal is larger than a distance from the centerline of the well to a point where the second seal contacts each of the ram block and the top seat when the ram block is in the closed position.