Pipeline corrosion is real, sure, and that's what I've found in the linked document. What I strongly doubt is that geomagnetic storms have any kind of importance to them.
Let focus on corrosion first ...
Corrosion is an electrochemical reaction involving the movement of electrons. Electrochemical reaction requires four elements, all of which must be in contact - the anode, the cathode, the conductive material, and the electrolyte.
Let assume the role of pipe to be anode and cathode at the same time, pipe could mix up with different metals with different galvanic series, so the more active elements become Anode, and the less active elements become Cathode. Would it be corrected? Furthermore, would the stable metal (pipe) generate induced current under the changing magnetic field from geomagnetic storms?
On the other hands, if the electrolyte is the water within the pipe, stable water is water which neither tends to be corrosive nor scale-forming, so stable water cannot be possible to be electrolyte in this case.
Would moving water be the critical factor to be electrolyte? which generate induced current by itself under the changing magnetic field from geomagnetic storms? which become catalyst as an electrolyte.
For Corrosion, do anyone have any suggestions on whether the moving electrons are generated from stable metal (pipe) or moving water under the changing magnetic field from geomagnetic storms?
Thanks, to everyone very much for any suggestions :>