Wellhead assembly for under-water wells

Claim 1

APPARATUS FOR USE IN WELLHEAD INSTALLATIONS INSTALLED BELOW THE SURFACE OF A BODY OF WATER FROM A REMOTELYPOSITIONED OPERATING PLATFORM POSITIONED ABOVE SAID BODY OF WATER, SAID APPARATUS COMPRISING AN UPWARDLY-EXTENDING TUBULAR WELL MEMBER HAVING A BORE THERETHROUGH FORMING VERTICAL WALLS MEANS FIXEDLY POSITIONED ABOVE A WELL BORE, FIRST LANDING SURFACE MEANS FORMED ON THE OUTER SURFACE OF SAID WALL MEANS SAID WELL MEMBER, AN EXTENSION SPOOL MEMBER HAVING A BORE THERETHROUGH FORMING VERTICAL WALL MEANS AND ADAPTED TO BE SECURED AS AN INDEPENDENT UNIT TO SAID WELL MEMBER, SAID SPOOL MEMBER BEING CONNECTIBLE IN TELESCOPIC RELATION ON THE OUTSIDE OF SAID VERTICAL WALL MEANS OF SAID WELL MEMBER AND HAVING SECOND LANDING SURFACE MEANS FORMED IN THE INNER WALL THEREOF FOR SEATING A WELLHEAD UNIT THEREON AND SEATING SURFACE MEANS FORMED ON THE INNER WALL THEREOF FOR SEATING ON AT LEAST A PORTION OF THE FIRST LANDING SURFACE MEANS OF SAID WELL MEMBER, SAID SPOOL MEMBER HAVING THIRD LANDING SURFACE MEANS FORMED ON THE INNER WALL THEREOF FOR SEATING PIPE HANGER MEANS THEREON, LATERALLY-EXTENDIBLE AND RETRACTABLE HOLD-DOWN LATCHING MEANS CARRIED IN THE WALL OF SAID SPOOL MEMBER AND POSITIONED IN ENGAGEMENT RELATIONSHIP WITH AT LEAST A PORTION OF THE ADJACENT WALL MEANS OF SAID WELL MEMBER IN TELESCOPIC RELATION WITH SAID SPOOL MEMBER BELOW THE SEATING SURFACE MEANS, AND REMOTELY-OPERABLE ACTUATING MEANS OPERATIVELY ENGAGEABLE WITH SAID LATCHING FOR SELECTIVELY MOVING SAID LATCHING MEANS TO ENGAGED AND DISENGAGED POSITIONS.