Conduit tube of an electrode device for electrically heating underground hydrocarbon resources

摘要

A conduit tube of an electrode device for electrically heating underground hydrocarbon resources, which comprises: a metal conduit tube and an electrically insulative covering adhered on and around the outer peripheral surface of said metal conduit tube, said electrically insulative covering being formed by adhering polyether/ether/ketone resin in powder form having particle size of a range of from 10 to 100 mu m on and around said metal conduit tube which has been preheated to a temperature range of from 350 DEG C. to 450 DEG C. by the electrostatic coating method, and fusion-bonding the electrically insulative covering material thereon at said temperature range of the preheating.