this truism seems to have escaped designers of previous down hole heating schemes the use of which essentially heats oil only as it enters the production tubing without effectively heating it so that it will reach the production tubing in the first place largely containing the heat below the level of the junction between the production tubing 12 and the perforated tubing 16 as is achieved through the current design has the effect of focusing the heat on the production formation itself this in turn heats oil and paraffin in situ and allows it to flow to the well bore for pumping thus u201c producing u201d first the viscous materials which are impeding flow and then the desired product of the well oil or gas stainless steel is chosen as the material for the juncture collars at and below the joinder of production tubing 12 and perforate tubing 16 because of its limited heat conductive properties physical and chemical attack of the electrical connections between the power leads and the heater rods of conventional heating systems as well as shorting of electrical circuits because of invasion of heater units by conductive fluids is another problem of the present art to which the present invention is addressed referring to fig2 the present inventor has discovered that to prevent the aforementioned electrical problems the internal connection for.