Abstract: A subsea well completion system having an improved tubing hanger that includes passageways through the hanger to one or more of the tubing annulus, the casing annulus and seals. The passageways may include vertically extending seal bores which are normally closed by check valves which may be operated to the open position. A tree adapter is connected to the tubing hanger and includes passageways coacting with the hanger passageways and includes externally connected side ports. The check valves may be selectively and remotely controlled externally of the completion system for monitoring the various annulus. The system may be abandoned by pumping cement through the passageways to seal them off and thereafter severing the completion system without the aid of a drilling rig.

Abstract: A subsurface well safety valve having a curved flapper closure member and method making. The curved flapper has a concave sealing surface coacting with a valve seat. A flow tube has a lower end contoured to the flapper sealing surface. A flapper can be made out of a tubular member in which the inside has been honed providing a flapper with a concave surface which forms a sealing surface.