Offshore production systems and methods relating thereto are disclosed. In an embodiment, the offshore production system includes a surface vessel. In addition, the offshore production system includes a closed-loop cooling fluid circulation system extending subsea from the vessel and configured to cool a cooling fluid. The closed-loop cooling fluid circulation system includes a first tendon having an upper end coupled to the surface vessel and a lower end coupled to the seabed. The first tendon is in tension between the upper end and the lower end. The first tendon is configured to flow the cooling fluid from the lower end of the first tendon to the upper end of the first tendon.

A tubular connection includes a first joint of casing having an integral box end with an internal female wedge threaded zone having wedge threads disposed on a portion of the integral box end, and a second joint of casing having an integral pin end with an external male wedge threaded zone having wedge threads disposed on a portion of the integral pin end. The external male wedge threads engage with the internal female wedge threads. The second joint of casing has an internal diameter D1, and also includes an internal annular recess with an internal diameter D2. D2 is greater than D1, and the annular recess is disposed longitudinally along an inner surface of the second joint of casing. The annular recess is positioned radially adjacent to a portion of the external male threads disposed on a lower portion of the pin end.

A tubular connection includes a first joint of casing having an integral box end with an internal female wedge threaded zone having wedge threads disposed on a portion of the integral box end, and a second joint of casing having an integral pin end with an external male wedge threaded zone having wedge threads disposed on a portion of the integral pin end. The external male wedge threads engage with the internal female wedge threads. The second joint of casing has an internal diameter D1, and also includes an internal annular recess with an internal diameter D2. D2 is greater than D1, and the annular recess is disposed longitudinally along an inner surface of the second joint of casing. The annular recess is positioned radially adjacent to a portion of the external male threads disposed on a lower portion of the pin end.

A double-layer coiled tubing double-gradient drilling system, on the basis of conventional drilling equipment, includes a double-layer coiled tubing system, spacer fluid, a downhole lifting pump system, throttling control systems and a data monitoring system. Power fluid enters an annular space of the tubing through an adapter, passes through a downhole lifting pump, enters an inner pipe through a bridge channel, and enters the bottom hole through the drill bit. Return fluid enters an annular channel of the tubing through a recovery hole, then enters the inner pipe through the bridge channel and enters the lifting pump, and then enters a solid control system through the adapter and the control systems in sequence. Gradient control of the bottom hole pressure is realized through monitoring of the spacer fluid and control of the drilling pump unit and throttling control systems. The problem of narrow safe drilling density window is solved.

The system for making or breaking the riser includes a robotic system. The robotic system includes one or more robotic arms configured to be disposed on a spider deck, and one or more riser-connection manipulation tools each having a camera and being configured to manipulate a riser connection, the camera being configured to capture an image of an object, wherein each robotic arm is configured to couple to one riser-connection manipulation tool. Further the system for making or breaking the riser includes a control system. The control system includes a robot controller in communication with the one or more robotic arms and configured to control the one or more robotic arms. The system for making or breaking the riser is configured to analyze the image to determine the location and orientation of the object and transmit the location and orientation of the object to the robot controller.

A connector system includes a first riser joint configured to form part of a riser. The first riser joint includes a pin. The connector system also includes a connector configured to couple to a wellhead assembly. The connector includes multiple collet segments that are configured to move radially-inwardly to engage the pin of the first riser joint.

A riser extending from a floating rig has a riser manifold. A rig manifold can be manipulated by an arm to couple in an automated manner to the riser manifold when running the riser from the rig. The riser and rig manifolds have mechanical connectors that mechanically connect them. Additionally, the manifolds have flow couplings mating together for conducting flow in at least one flow connection, and the manifolds control couplings mating together for conducting control in at least one flow connection. At least one of the manifolds has at least one valve controllable with the at least one control connection and configured to control fluid communication for the at least one flow connection between at least one rig flow line and an internal passage of the riser.

A joint assembly allows a riser system to have a weak point that can fail at a known location and tension value without reducing the riser pressure containment capacity. The joint assembly includes a standard riser pipe machined to remove material, for example, to form a groove. The joint assembly also comprises means for restoring pressure capacity. For example, the means for restoring pressure capacity include a combination of a thick-bodied clamp and a split insert ring. The split insert ring can bridge between the groove and the clamp, at least partially transferring the pressure load contained inside the machined pipe to the clamp.

A method for forming a sleeve for wrapping around and insulating a joint of a downhole tubing string is provided. The method includes the steps of providing a mold, applying insulation around the mold, winding an interfacing material around the insulation; and applying a polymer onto the interfacing material to bind to the interfacing material to form the sleeve.

A weldless adapter is mountable to a conductor casing for pressure testing seals or initial drilling at a well site. Slips engage the conductor casing to latch the weldless adapter onto the casing. Pressure injection ports are utilized to activate two seal rings against the conductor casing using positive sealing. A test port is utilized to test the seals of the two seal rings. The slips are activated by three sets of bolts.