Blowout preventer and method of insuring prevention of fluid leaks out of a wellhead

A method of and apparatus for preventing fluid leaks out of a well which involves installing a blowout preventer at a wellhead, the preventer has a body with a bore communicating with a bore hole and a clamping means for controlling the passage of fluid through the bore. Means are provided for directing sealant into the bore beneath the clamping means so that when an occurrence of a blowout is sensed, the clamping means are closed to inhibit flow of fluid up the bore and a sealant is injected through the directing means into the bore so that the sealant is carried to the closed clamping means which forms a seal to insure that fluid does not leak past the closed clamping means.