| 摘要 |
The present invention relates to an offshore installation including an oil/gas flowline umbilical installed between a platform-or a shore installation-and a sea bed based template and including an insulated electrical cable conductor connected in series with the steel oil/gas pipe to a power supply. The main features of the invention is that the far end interconnection between the cable conductor (or parallel cable conductors) and the pipe is grounded to seawater to provide a single point grounded system, such that all the current flows in the selected cable conductors, and the system has zero volts at the far end whereby no current is transmitted though the sea. The power supply is insulated from ground and the current is fed from the power supply through the pipe, and returns through the cable, whereby a voltage level of zero Volts is obtained at the far end where the system is grounded, and all the current is forced through the cable(s) and the pipe/flowline.
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