System and system elements for direct electrical heating of subsea pipelines
AssigneeSinvent AS
InventorsJens Kristian Lervik, Harald Kulbotten
Life of this patent
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Abstract
A device for high efficiency induction heating or direct electrical heating, DEH, of a number, M, Mε[1, N of a group of parallel subsea pipelines N, where Nε[2, ∞, and where a number of conductor cables, W, supplies electrical power from at least one top side power supply to M of the parallel subsea pipelines N, wherein the number of electric conductors, W, from the at least one top side power supply connected to the M pipelines is defined to be in the group Wε[N, N+1], where N, W and M are natural numbers.
Claims19
A device for high efficiency induction heating or direct electrical heating, of a plurality, M, of pipelines, where Mε[1, N of a group of parallel subsea pipelines N arranged adjacent to each other, where Nε[2, ∞, and where a number of conductor cables, W, supplies electrical power from at least one top side power supply to M of the parallel subsea pipelines N, wherein the numbers of electric conductors, W, from the at least one top side power supply connected to the M pipelines is defined to be in the group Wε[N, N+1], where N, W and M are natural numbers, and wherein a second power supply G2 is provided to supply current in a reduction transfer current cable routed in parallel to the heated pipeline(s) M at a distance, d, the current through the reduction transfer current cable is adjusted to equal the absolute value of a steady state current in seawater, thereby reducing current transfer through CTZ.
A system for direct electrical heating or induction heating of at least a first of at least two parallel subsea pipelines comprising power cables in which at least one supplies electric power from a top side to the at least first of at least two parallel subsea pipelines, where the system further comprises,
- at least one power supply at the top side;
- at least one riser cable including at least two power cables;
- and
- at least two connections from the at least two power cables from the at least one riser, one connection to a return power cable at a near end Current Transfer Zone, where the return cable runs in parallel with a second pipeline and is connected to the second pipeline at a far end Current Transfer Zone and one connection to a power supply cable at the near end Current Transfer Zone which runs in parallel with the first pipeline and which is connected to the far end Current Transfer Zone of the first pipeline.
A device for high efficiency induction heating or direct electrical heating, of a plurality, M, of pipelines, where Mε[1, N of a group of parallel subsea pipelines N arranged adjacent to each other, where Nε[2, ∞, and where a number of conductor cables, W, supplies electrical power from at least one top side power supply to M of the parallel subsea pipelines N, wherein the numbers of electric conductors, W, from the at least one top side power supply connected to the M pipelines is defined to be in the group Wε[N, N+1], where N, W and M are natural numbers where at least a first of two pipelines are supplied with electric power at a far end Current Transfer Zone of the at least two pipelines, and where the electric power at the far end of two pipelines, the first and a second pipeline, is fed by one power cable which runs in parallel to the two pipelines and which is connected to the first pipeline at the far end Current Transfer Zone, current is transferred through the first pipeline to a near end Current Transfer Zone, at the near end Current Transfer Zones the first pipeline is electrically connected to the second pipeline, current is transferred through the second pipeline to the far end Current Transfer Zone, whereas return current is returned to a riser by one power cable connected to the second pipeline at the far end Current Transfer Zone and wherein a short circuit connection is connected between the connections at the far and near end Current Transfer Zones of the two pipelines.
Dependencies are inferred from the claim text.