Abstract:
A section of riser casing urges drilling mud upward from the sea floor to reduce head pressure associated with pumping drilling mud through riser casing in dual-gradient drilling operations. The section of riser casing may use an electromagnet, two or more electrodes, or a combination of electromagnets and electrodes to urge drilling mud having electrohydrodynamic properties through the riser casing.
Abstract:
A wellhead or Christmas tree seal assembly that forms a metal-to-metal seal between inner and outer wellhead or Christmas tree members. U-shaped metal seals having legs that face in opposite directions, are bonded to a wiping element. During installation of the seal assembly, the ends of the seal legs seal against the wellhead members and the wiping element compensates for defects on the surfaces of the wellhead members. The wiping element can be of an elastomer, metallic, or intercalated graphite material.
Abstract:
A high capacity running tool sets and internally tests a casing hanger packoff during the same trip. The running tool has a stem and a body. The body is secured by threads to the stem of the running tool so that rotation of the stem relative to the body will cause the stem to move longitudinally. An engagement element connects the tool body to the casing hanger by engaging the inner surface of the casing hanger. Longitudinal movement of the stem relative to the body moves the engaging element between inner and outer positions and lines up ports in the stem and in the body for setting and testing functions.
Abstract:
A tieback connector connects a tieback conduit from an offshore platform to a subsea wellhead assembly. The tieback connector has a mandrel that is connected to a string of tieback conduit and a sleeve and load ring that are carried by the mandrel. The load ring is radially expansible and has a conical portion with internal threads. The load ring has an external grooved profile that engages an internal grooved profile in the subsea assembly. The mandrel is rotatable relative to the sleeve while in its lower position, causing the load ring to further expand outward into engagement with the internal profile. A locking member is carried below the load ring on an exterior cam surface of the mandrel. The cam surface moves the locking member outward when the mandrel moves downward into engagement with an internal profile in the subsea assembly.
Abstract:
A connector assembly for connecting two members that allows manual lockdown to prevent accidental disengagement. The connector assembly can be used to connect a tension ring to a housing on a riser by using a lower set of hydraulically actuated dogs. A set of upper hydraulically actuated dogs on the connector assembly can be used to connect the tension ring to a diverter housing mounted on a rig. The connector assembly also has position indicators that ride along with the dogs to indicate whether the dogs are in the engaged or disengaged position.
Abstract:
A wellhead seal assembly forms a metal-to-metal seal between inner and outer wellhead members. A metal seal ring has inner and outer walls separated by a slot. An energizing ring has a C-ring captured on its outer surface. When the energizing ring is moved further into the slot, the C-ring is forced from its pocket and engages a profile on the seal ring, locking the energizing ring to the seal assembly.
Abstract:
A riser tensioner configured to apply a tension to a riser. The riser tensioner includes a frame configured to be fixedly attached to the riser; plural cylinder assemblies spaced around the riser, each cylinder assembly having a cylinder and a piston configured to slidably move inside the cylinder, the piston being configured to connect to the frame; a guide roller support stationarily mounted to and extending from the frame; at least one bearing fixedly attached to the guide roller support; and a guide member configured to be in rolling engagement with the at least one bearing as the cylinder moves relative to the frame.
Abstract:
A drilling system employs a set of bushings that protect seats used for casing hangers. The system includes one or more seat protectors that attach to a running tool. The running tool is lowered down the wellbore with the seat protectors attached and deposits a bushing at each surface to be protected. The running tool may retrieve the bushings as the running tool is withdrawn from the wellbore.
Abstract:
A wellbore system comprising a housing assembly and a hanger assembly. The hanger assembly comprises an actuation member that interacts with a portion of the housing assembly when the hanger assembly is positioned at a desired location in the housing assembly. The hanger assembly also comprises a load member that is adapted to extend between the hanger assembly and the housing assembly to enable the housing assembly to support the hanger assembly. The load member is carried into the wellbore in a retracted position. When the actuation member interacts with the housing assembly at the desired location, the actuation member actuates the load member to expand outward to extend between the hanger assembly and the housing assembly. The actuation member is adapted to transfer a lifting force from the surface to the load member to enable an over-pull test of the hanger assembly to be performed.
Abstract:
A subsea wellhead assembly for a subsea well including a low pressure wellhead housing having a string of conductor piping extending therefrom. A high pressure wellhead housing, having a string of outer casing suspended therefrom, lands within the low pressure wellhead housing. The high pressure wellhead housing has a housing bore. An adapter is positioned within the housing bore. The adapter has an external load shoulder that lands on a housing load shoulder of the high pressure wellhead housing. The adapter also has an adapter bore with an inner adapter load shoulder formed thereon. A casing hanger is carried in the adapter bore, and has a string of inner casing suspended therefrom and is cemented in the well. The casing hanger lands on the inner adapter load shoulder.