GB984736A - Wellhead assembly - Google Patents

Abstract

984,736. Wells. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. June 18, 1963 [June 20, 1962], No. 24229/63. Heading E1F. A wellhead, particularly a sub-aqueous wellhead, comprises a casing string 21, a tubing string 43 within the string 21, a housing secured to the string 21 and having a chamber 56 communicating with the string 21, a conduit 60 in the housing and in communication with the string 43, a conduit 61 beside the conduit 60 and communicating with the chamber 56, a chamber 91 at the top of and communicating with the conduit 61, and above the chamber 91 a passageway 102 communicating with the conduit 60 and disposed within a passageway 104 communicating with the chamber 91. The apparatus below the lower part of the spool 57 forms the subject matter of Specification 932,119. The spool 57 carries valves 62a, 63a controlling branches 60a, 61a from the conduits which are continued through a spool 85 having conduit control valves 62, 63. The spool 85 carries a lubricator housing 86 comprising outer, intermediate and inner members 93, 98, 92, the housing 86 being closed by a plug 97 during production. With the plug removed pressure may be applied to a line 107 to open the valves 62, 63 and close valves 62a, 63a to permit operations to be carried out through the conduits 60, 61. The plug which has sleeve valves 120, 121 and ducts preventing the build up of pressure or the creation of a vacuum during insertion into or removal from the housing 86 is fixed to the housing by latches 112, 113. Specification 920,309 also is referred to.