The present invention provides a system for coupling between a bend stiffener (1) and a bell month (2) comprising a plurality of locking mechanisms (3), wherein each locking mechanism (3) is secured externally to the bell mouth (2) and comprises a movable lug (30) positioned such as to slope downwards, in which the lug (30) accesses the interior of the bell mouth (2) and is actuated by an elastic element (34) designed to exert pressure on the lug (30) in the direction of the interior of the bell mouth (2).

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 device (10) for monitoring strain of an elongate member (12) is deployed underwater. The device (10) comprises a first clamp (14) configured to embrace and couple to the elongate member (12) at a first axial location, a second clamp (16) configured to embrace and couple to the elongate member at a second axial location separated from the first axial location, and a sensor which is responsive to an angle between the first clamp and the second clamp.

A device (10) for monitoring strain of an elongate member (12) is deployed underwater. The device (10) comprises a first clamp (14) configured to embrace and couple to the elongate member (12) at a first axial location, a second clamp (16) configured to embrace and couple to the elongate member at a second axial location separated from the first axial location, and a sensor which is responsive to an angle between the first clamp and the second clamp.

A system includes a first split riser, a second split riser, and a gasket. The first split riser includes a first half pipe having a first radial extension and a second radial extension. The first radial extension and the second radial extension have a mating surface. The second split riser includes a second half pipe having a third radial extension and a fourth radial extension. The third radial extension and the fourth radial extension have a corresponding mating surface. The gasket is installed on the mating surface of the first radial extension and the second radial extension. The gasket mates with the corresponding mating surface to form a connection between the first split riser and the second split riser.

A system includes a first split riser, a second split riser, and a gasket. The first split riser includes a first half pipe having a first radial extension and a second radial extension. The first radial extension and the second radial extension have a mating surface. The second split riser includes a second half pipe having a third radial extension and a fourth radial extension. The third radial extension and the fourth radial extension have a corresponding mating surface. The gasket is installed on the mating surface of the first radial extension and the second radial extension. The gasket mates with the corresponding mating surface to form a connection between the first split riser and the second split riser.

An improved swivel with increased sealing capability at fluid pressures up to 20 ksi and at fluid temperatures as high as 250° F. and as low as 35° F. The swivel may be relatively compact, being less than 8 feet in overall length and can operate unpressurized with axial loads of at high as 1,400,000 lbs. The swivel may comprise a swivel mandrel rotationally coupled with a swivel housing. Rotational bearings units can be securely held using cartridge carriers. A pressure seal may be formed between the swivel mandrel and swivel housing via a redundant seal stack.

An improved swivel with increased sealing capability at fluid pressures up to 20 ksi and at fluid temperatures as high as 250° F. and as low as 35° F. The swivel may be relatively compact, being less than 8 feet in overall length and can operate unpressurized with axial loads of at high as 1,400,000 lbs. The swivel may comprise a swivel mandrel rotationally coupled with a swivel housing. Rotational bearings units can be securely held using cartridge carriers. A pressure seal may be formed between the swivel mandrel and swivel housing via a redundant seal stack.

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.

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.