The exploitation of heavy oil in the future will require new technical solutions for more efficient production. One of them is the oil well heating by electric heating cable. So far a rare use of devices with heating cable for paraffin deposition prevention has resulted in an invention of a new technical solution. The developed device has an original way of very simple installation of the heating cable into the well, and so overcomes the main disadvantage of existing devices. Also, the device heating control unit precisely doses the needed amount of heat for oil heating that makes device energy efficient. Using of this technical solution increases well productivity by improvement of heavy oil rheological properties. The new device has been tested and the results are presented in this paper. It has been patented, and has won several awards. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.