Well pressure control apparatus

Claim 1

IN A WELL HAVING OUTER CASING, INNER CASING AND WELL TUBING, APPARATUS COMPRISING A BODY MEMBER ADAPTED TO BE ATTACHED TO AND SUPPORTED ON THE UPPER END OF THE OUTER CASING, SAID BODY MEMBER HAVING A VERTICAL OPENING AXIALLY THERETHROUGH, SAID OPENING HAVING AN UPWARDLY FACING SHOULDER BETWEEN A RELATIVELY ENLARGED UPPER BOWL PORTION AND A RESTRICTED LOWER PORTION THEREOF, A FIRST HANGER FOR THE INNER CASING DISPOSED IN THE BOTTOM OF SAID BOWL PORTION, SAID HANGER HAVING AN INTEGRAL ANNULUS PROJECTING FROM ITS BOTTOM INTO THE SAID LOWER PORTION FOR ATTACHING THE UPPER END OF THE INNER CASING THERETO, SAID ANNULUS BEING SPACED FROM THE BODY TO FORM AN ANNULAR OPENING THEREBETWEEN IN COMMUNICATION WITH THE SPACE BETWEEN THE INNER AND OUTER CASING, SAID HANGER HAVING A VERTICAL AXIAL OPENING THERETHROUGH THREADED AT EITHER END, A SECOND HANGER FOR THE WELL TUBING IN THE SAID BOWL PORTION ABOVE SAID FIRST HANGER, SAID SECOND HANGER HAVING A VERTICAL OPENING THERETHROUGH THREADED AT EITHER END; MEANS REMOVABLY SECURING SAID HANGERS TO SAID BODY; HIGH PRESSURE FLUID SEALING MEANS BETWEEN SAID BODY AND HANGERS; SAID FIRST HANGER HAVING A PLURALITY OF DUCTS EXTENDING FROM THE TOP THEREOF TO SAID SHOULDER; SAID FIRST HANGER AND SAID SHOULDER HAVING A CHANNEL THEREBETWEEN FORMING A BOTTOM MANIFOLD FOR SAID DUCTS; SAID HANGERS HAVING AN ANNULAR CHANNEL THEREBETWEEN AT THE UPPER ENDS OF THE DUCTS FORMING A TOP MANIFOLD FOR SAID DUCTS; SAID LAST MENTIONED CHANNEL BEING IN COMMUNICATION WITH THE AXIAL OPENING IN SAID FIRST TUBING HANGER; SAID BODY HAVING PASSAGEWAYS THERETHROUGH EXTENDING TO ITS EXTERIOR COMMUNICATING WITH SAID TOP MANIFOLD AND WITH SAID ANNULAR OPENING, RESPECTIVELY; AND CONTROL VALVES CONNECTED TO SAID PASSAGEWAYS.