CO.sub.2 in the liquid or super-critical state is delivered by at least one carrier vessel from at least one CO.sub.2 storage site, which may be an onshore site, to an integrated offshore facility. The integrated offshore facility is provided with at least one on-site storage tank or vessel adapted to store CO.sub.2 in the liquid or super-critical state and with equipment for marine transfer of CO.sub.2 in the liquid or super-critical state. CO.sub.2 is utilised as required from said at least one on-site storage tank or vessel for EOR at said offshore site or for EGR at said offshore site by injection into a sub-sea oil or natural gas bearing reservoir and recovery of oil and/or natural gas from a resulting production stream.

An arrangement and system places an external cable into a slot. The arrangement includes a slot extending from a first end to a second end. The slot includes a recess configured to receive a cable therein. The arrangement includes a movable component configured to slide along a length of the slot. The movable component includes a first end and a second end. Sliding the movable component along the slot in a first direction from the first end to the second end of the slot one of frees a first portion of the cable from the slot or places a second portion of the cable in the slot.

An arrangement and system places an external cable into a slot. The arrangement includes a slot extending from a first end to a second end. The slot includes a recess configured to receive a cable therein. The arrangement includes a movable component configured to slide along a length of the slot. The movable component includes a first end and a second end. Sliding the movable component along the slot in a first direction from the first end to the second end of the slot one of frees a first portion of the cable from the slot or places a second portion of the cable in the slot.

A hydraulically driven underwater pumping system may include a pumping module connected to a subsea base. The subsea base may be connected to: a subsea producing well via a production line that carries the fluid produced by the subsea producing well; and a production unit via a riser and a service line. The hydraulically driven underwater pumping system may receive working fluid from the production unit via the service line. Additionally, a pump, located in the pumping module, may be driven hydraulically by the working fluid and pump the fluid produced by the subsea producing well to the production unit. The hydraulically driven underwater pumping system may mix the working fluid, after being used to drive the pump, with the fluid produced by the subsea producing well that is pumped to the production unit.

A hydraulically driven underwater pumping system may include a pumping module connected to a subsea base. The subsea base may be connected to: a subsea producing well via a production line that carries the fluid produced by the subsea producing well; and a production unit via a riser and a service line. The hydraulically driven underwater pumping system may receive working fluid from the production unit via the service line. Additionally, a pump, located in the pumping module, may be driven hydraulically by the working fluid and pump the fluid produced by the subsea producing well to the production unit. The hydraulically driven underwater pumping system may mix the working fluid, after being used to drive the pump, with the fluid produced by the subsea producing well that is pumped to the production unit.

Installation for producing fluid such as crude oil having a floating support having at least two tanks, an undersea bottom-to-surface connection pipe having a first pipe portion on the sea bottom from a well head to the bottom end of a second pipe portion at the floating support, a first auxiliary pipe for transporting gas extending from the floating support to the bottom end of the second pipe, and a plurality of valves for isolating or putting into communication the first auxiliary pipe, for isolating or putting into communication the first production pipe portion and the second production pipe portion, end to end, and suitable for isolating or putting into communication the proximal end of the first production pipe portion and the bottom end either of a fourth auxiliary pipe rising directly to the surface, or a bottom portion of the first auxiliary pipe.

Installation for producing fluid such as crude oil having a floating support having at least two tanks, an undersea bottom-to-surface connection pipe having a first pipe portion on the sea bottom from a well head to the bottom end of a second pipe portion at the floating support, a first auxiliary pipe for transporting gas extending from the floating support to the bottom end of the second pipe, and a plurality of valves for isolating or putting into communication the first auxiliary pipe, for isolating or putting into communication the first production pipe portion and the second production pipe portion, end to end, and suitable for isolating or putting into communication the proximal end of the first production pipe portion and the bottom end either of a fourth auxiliary pipe rising directly to the surface, or a bottom portion of the first auxiliary pipe.

A subsea riser is installed by lowering at least one riser conduit to the seabed when piggybacked to an elongate support that comprises at least one flowline. The elongate support may be a pipeline bundle, which may be attached to one or more towheads in a towable bundle unit. The riser conduit may be in fluid communication with the flowline. At the seabed, a free end portion of the riser conduit is detached from the elongate support by releasing subsea-releasable fastenings. Then, with the elongate support and a root end of the riser remaining at the seabed, the detached free end portion of the riser conduit is lifted away from the elongate support to a riser support, such as a platform, an FPSO (floating production, storage and offloading vessel), or a buoy.

A subsea riser is installed by lowering at least one riser conduit to the seabed when piggybacked to an elongate support that comprises at least one flowline. The elongate support may be a pipeline bundle, which may be attached to one or more towheads in a towable bundle unit. The riser conduit may be in fluid communication with the flowline. At the seabed, a free end portion of the riser conduit is detached from the elongate support by releasing subsea-releasable fastenings. Then, with the elongate support and a root end of the riser remaining at the seabed, the detached free end portion of the riser conduit is lifted away from the elongate support to a riser support, such as a platform, an FPSO (floating production, storage and offloading vessel), or a buoy.

Disclosed are systems and methods for thermal management of subsea conduits such as jumpers that provide the ability to alternate between cooling and heat retention of production fluids within the conduit as needed depending on the phase of operation. Adjustable insulation elements are provided on the conduits so that convective heat transfer between surrounding seawater and the conduit can be allowed or reduced. A control system can activate an alarm indicating the need to adjust the insulation depending on the temperature and/or flow rate of fluids in the conduit. Conventional conduits can be retrofitted by adding adjustable insulation elements to enable thermal management.