Abstract: A method and apparatus for making an electrical connection through a tubing hanger in a subsea well avoids the need for precise gauging and alignment. The tubing hanger has an electrical receptacle located on its rim and a guide hole also located on the rim. An impression block tool is lowered into the wellhead from the surface to make an impression of the rim to determine the orientation of the guide hole. A carrier is mounted to the tree connector at the surface. The carrier has a guide pin and an electrical connector. The carrier is aligned, then secured to the tree connector so that it can move only a limited amount rotationally. As the tree connector enters the wellhead, the guide pin will enter the guide hole, which is tapered. A limited amount of rotation of the carrier relative to the tree connector allows the electrical connectors to precisely align before contacting each other.

Abstract: A quick disconnect coupling for a subsea well flowline has valves that open and close when the coupling is made up and released. The coupling has tubular upper and lower connectors, each with a flow passage. The upper connector inserts over a mandrel of the lower connector. Ball valves are located in the passage of each connector. A latch member engages the mandrel when moved by a hydraulically actuated piston and a cam. A gear assembly connected with the piston simultaneously moves the upper ball valve to the closed position. A gear assembly connected with the lower ball valve simultaneously opens the lower ball valve when the upper connector latches to the lower connector.

Abstract: A riser string for a subsea well uses the outer conduit or air can members to support the weight of the riser string. The outer conduits have flanges on their ends which are bolted together. The outer conduits have ports to admit sea water, and a gas injection system to displace some of the sea water for providing buoyancy. Mounting plates are located at each end of the outer conduits. Inner conduits for conveying well and production fluids are mounted between these mounting plates. The mounting plates are intrinsically curved in vertical cross-section, such that when the conduit flanges are bolted together, the mounting plates flatten to provide a compressive force across the faces. Metal seals are located in the holes provided in the mounting plates for the inner conduits. The inner conduits are supported along their lengths by one or more lateral supports.

Abstract: An expanding gate valve having seats (74) which are mechanically secured in place. The valve body has seat pockets which include undercut grooves (78) intersected by a cylindrical body cavity (24) to form a pair of openings (80) to each groove. Each valve seat has a pair of lugs (90) which may be fitted through the openings and into the undercut groove. Subsequent rotation of the seat locks the lugs in the groove to secure the seat in place in its seat pocket. Each seat is able to pivot about an axis extending between the lugs in order to compensate for irregularities in the contact surfaces of the gate or seat.

Abstract: A metallic seat assembly for a gate valve includes an annular seat pocket around the flow passageways to the valve chamber with a metallic annular seat support member rigidly mounted in the seat pocket and a metallic annular seat member movably mounted inside the seat support member and connected thereto by a resilient and flexible annular metallic member. The resilient annular member is secured continuously around its inner and outer perimeters to the seat support member and the seat member respectively and it functions as a spring to bias the seat member toward the gate and as a seal between the seat member and the supporting member. The resilient and flexible member permits axial movement of the seat member relative to the seat support member and also compensates for thermal expansion and contraction of the seat member and the seat support member relative to each other. The metallic seat member has an integral metallic sealing lip extending from an annular groove around the sealing face of the seat member.

Abstract: A limited float or controlled float seat assembly for a gate valve with a transversely expandable gate assembly has generally L-shaped annular seat retainers fixed in recesses around the valve inlet and outlet flow passageways and generally L-shaped annular seat members mounted in a complementary relation within each of the seat retainers. The seat retainers each have an inturned lip opposite to and spaced from the end of the recess. The inturned lips form limit stops for the seat members. The seat members have an outturned lip which contacts the inturned lip of the seat retainer thereby limiting movement of the seat member when the seat member moves to an extended position. The combined amount of float for both seat members is less than the total expansion of the gate assembly from a collapsed position to an expanded position where it seals with the seat members so that drag of the seat members on the gate assembly is minimized.

Abstract: A valve actuator for an expanding gate valve having a gate and a segment thereon. The actuator includes a piston connected to a gate stem and mounted within a cylinder with a pressurized gas on the upper side of the piston and liquid on the lower side of the piston. The gate valve moves from an open position to a closed position across the flow passage at a rapid rate and decelerates adjacent the end of its downward movement upon a metering of the liquid in the cylinder. The expanding gate valve expands laterally into fluid-tight sealing relation at the end of the downward stroke after moving across the flow passage. The bonnet is mounted internally of the valve body and a pressure seal is positioned between the bonnet and the valve body to permit operation of the valve actuator and gate valve even after failure of the pressure seal.