HEATING CABLE Russian patent published in 2003 - IPC

FIELD: electric path-control heating of viscous and very viscous oil-gas mixtures. SUBSTANCE: proposed heating cable designed for reducing viscosity of oil-gas- mixtures using any desired way of extracting oil from deep and very deep oil wells to eliminate and prevent formation of asphaltene, pitch, and wax deposits by controlling heat power dissipation has at least one insulated conductor bent to form at least one loop; branches of this loop run unidirectionally from point of bend and either come in contact with or are separated from each other. Branches come in contact over helical line. One and/or both branches may be stranded over helical line. Lay of strand over helical line may be constant and/or varying. Conductors may be equal or unequal in length. Branches may be also equal or unequal in length. Insulated conductors may be covered with protective sheath overall. Each conductor may be made of conducting material having different conductivity. Loop outline may be shaped as arc, open rectangle, square, polygon, or triangle. EFFECT: enhanced operating reliability and enlarged range of selection of heating cables. 11 cl, 5 dwg