The present invention relates to an arrangement in a pipe bundle, more specifically to a method and a system for heating subsea or on-shore pipelines, especially pipelines for transportation of substantially oil, gas and water, said pipelines (8, 108, 208) being arranged in a substantially cylindrical outer carrier pipe (1, 101, 201), and for the purpose of providing an arrangement wherein the quantity of heating cable can be reduced, and wherein the manufacturing of such arrangement can be simplified, at the same time as the finished arrangement will provide appropriate heating of the pipelines and the contents thereof, it is according to the invention suggested an arrangement comprising: a carrier pipe (1, 101) having an outer and/or inner thermal insulation (2, 102), one or more longitudinally extending energy carriers (3, 4, 5; 103, 104, 105) extending in the longitudinal direction of said carrier pipe (1, 101) for the dissipation/transfer of heat directly and/or indirectly to said pipelines (8, 108), respectively said pipe bundle or bundles, and thereby to the contents of said pipelines.
A novel system for inductively heating a fluid conduit using an electrical cable located proximate the fluid conduit. Electricity is conducted to the cable in either a powering mode, in which a powered system is electrically coupled to the cable and substantially no inductive heating of the fluid conduit is provided, or a heating mode, in which the powered system is electrically decoupled from the cable and inductive heating of the fluid conduit is provided.
The present invention concerns a device for heat-insulating at least one sub-marine pipe. The sub-marine pipe includes a heat insulation covering including a material subject to migration, the covering surrounding the pipe and being covered by a sealed protective envelope having a tubular shape and a longitudinal axis of symmetry. The envelope being constituted by a flexible or semi-rigid material able to remain in contact with the external surface of the insulation covering when the latter warps. The device includes at least two sealed transversal partitions, each being constituted by a closed rigid piece traversed by and integral with the pipe and with the envelope.
Hydrocarbon liquids are transported from a subsea welihead to an above-surface hydrocarbon processing facility along a pipe-in-pipe flowline. The flowline is a pipe placed coaxially within an outer carrier pipe and the annulus between the pipes is filled with thermally insulating material. The hydrocarbon liquids have their temperature maintained above solidification/precipitation temperature by heat from an active heating system. Hot liquid, preferably hot water, is passed along the annulus, either along a single pipe or multiple pipes installed in the insulation-filled annulus, or along an inner annulus formed by a water pipe added concentrically around the hydrocarbon-transporting inner pipe, inside the outer insulation-filled annulus. The water or other suitable liquid can be heated in a heater at or adjacent the subsea wellhead, or by a water heater in the above-surface hydrocarbon processing facility.
An elongated object for use in subsea having a heating pipe and an electrical cable fixed to the surface of the heating pipe. The electrical cable has a protective sleeving for surrounding the electrical cable, composed of a series of elongated synthetic plastics components arranged end-to-end. Each component is an extruded frame work type hollow profile suitable for slowing down the impact over a long deformation path. A hollow space is disposed between the electrical cable and the protective sleeving allowing the cable to move into the protective sleeving.
A method of controlling the heat transfer properties of a sub-sea conduit having inner and outer walls (800, 802) and a gas-permeable space (804) between the walls providing thermal insulation, the method comprising varying the pressure of a gas within the space between values above and below a critical pressure range at which thermal conductivity of the gas exhibits a high rate of change.
