Data transfer
AssigneeFlight Refuelling Limited
InventorsNeil M. Dickie, Steven M. Hudson
Life of this patent
Estimating the term…
Abstract
A sub-sea oil pipeline installation comprising a production platform (10) and sub-sea facilities (15) at a plurality of well-heads (16), has a data transmission system by which data is transmitted in either direction between the master platform (10) and the sub-sea facilities (15) via communication channels formed by the electrically conducting material of the pipelines (12, 14). The data is transmitted in the form of a VLF or ELF electro-magnetic signal which comprises changes of voltage level oscillating about the DC voltage level of the pipe (12, 14) so that the mean level of the signal is the DC voltage level of the pipe (12, 14).
Claims16
A pipeline system comprising a metal pipeline having a coating of insulating material which, in conjunction with sacrificial anodes electrically connected to the pipe provides cathodic protection, there being signal generating means adapted to be coupled to the pipeline and operable when so coupled to apply data to be transmitted in signal form to the pipeline for conveying along an electrically conducting channel formed by the metal pipeline, wherein the improvement comprises the signal generating means being operable to generate as the signal a pulsed electro-magnetic signal which comprises changes of voltage level in a very low frequency range (VLF and below), and further including means operable to use data transmitted via the channel provided by the pipeline for monitoring the condition of the insulation of the pipeline.
A pipeline system comprising a metal pipeline having a coating of insulating material which, in conjunction with sacrificial anodes electrically connected to the pipe provides cathodic protection, there being signal generating means adapted to be coupled to the pipeline and operable when so coupled to apply data to be transmitted in signal form to the pipeline for conveying along an electrically conducting channel formed by the metal pipeline wherein the improvement comprises the signal generating means being operable to generate as the signal a pulsed electro-magnetic signal which comprises changes of voltage level in the very low frequency range, the signal generating means being operable to generate the electro-magnetic signal in the very low frequency range so that it comprises changes of voltage level oscillating about the DC voltage level of the pipeline so that the mean level of the signal is substantially the DC voltage level of the pipeline.
A pipeline system comprising a metal pipeline having a coating of insulating material which, in conjunction with sacrificial anodes electrically connected to the pipeline provides cathodic protection, and signal generating means adapted to be coupled to the pipeline and operable when so coupled to apply data to be transmitted in signal form to the pipeline for conveying along an electrically conducting channel formed by the metal pipeline, wherein the improvement comprises the signal generating means being operable to generate as the signal a pulsed electro-magnetic signal which comprises changes of voltage level in a very low frequency range (VLF and below), and wherein means are provided which are operable to use data transmitted via the channel provided by the pipeline to monitor a characteristic impedance of the pipeline and thereby monitor the condition of the insulation of the pipeline.
A pipeline system comprising a metal pipeline having a coating of insulating material which, in conjunction with sacrificial anodes electrically connected to the pipeline provides cathodic protection, and signal generating means adapted to be coupled to the pipeline and operable when so coupled to apply data to be transmitted in signal form to the pipeline for conveying along an electrically conducting channel formed by the metal pipeline, wherein the improvement comprises the signal generating means being operable to generate as the signal a pulsed electro-magnetic signal which comprises changes of voltage level in a very low frequency range (VLF and below), and wherein means are provided which are operable to use data transmitted via the channel provided by the pipeline to determine a time history of errors in a carrier signal and thereby monitor the condition of the insulation of the pipeline.
Dependencies are inferred from the claim text.