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A method for manufacturing an electrical cable provides an electrical cable suitable for use in heating wells. An elastomeric jacket is extruded over insulated conductors. A stainless steel plate is rolled around the jacket to form a cylindrical coiled tubing having a seam. The seam is welded, then

A method for manufacturing an electrical cable provides an electrical cable suitable for use in heating wells. An elastomeric jacket is extruded over insulated conductors. A stainless steel plate is rolled around the jacket to form a cylindrical coiled tubing having a seam. The seam is welded, then the tubing is swaged down to a lesser diameter to cause the tubing to frictionally grip the jacket. A recess may be formed in the jacket adjacent the seam to avoid heat damage from the welding process.

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1. A cable for deployment in a well, comprising: at least one insulated conductor; an elastomeric jacket extruded over the insulated conductor, the jacket having a cylindrical exterior that has a longitudinally extending recess formed thereon; and a metal tubing having a cylindrical inner wall

1. A cable for deployment in a well, comprising: at least one insulated conductor; an elastomeric jacket extruded over the insulated conductor, the jacket having a cylindrical exterior that has a longitudinally extending recess formed thereon; and a metal tubing having a cylindrical inner wall and a longitudinally extending weld seam, the tubing enclosing the jacket with the inner wall in frictional engagement with the cylindrical exterior of the jacket, the seam being located adjacent the recess so as to avoid excessive heat to the jacket while the seam is being welded. 2. The cable according to claim 1, wherein the recess intersects the cylindrical surface at two points in the range from 50 to 90 degrees apart. 3. The cable according to claim 1, wherein the recess has a base that is located a selected distance from the seam, the selected distance divided by a radius of the inner wall of the tubing being in the range from 0.15 to 0.35. 4. The cable of claim 1, wherein the tubing is formed of stainless steel. 5. The cable of claim 1, wherein the exterior of the jacket has a plurality of longitudinally extending grooves formed thereon. 6. The cable of claim 1, wherein the material of the jacket is an EPDM. 7. The cable of claim 1, wherein the insulated conductor has an inner layer of a polyimide material and an outer layer of a fluoropolymer material. 8. The cable of claim 1, wherein the tubing has an outer diameter no greater than one inch. 9. A cable for applying heat to a well, comprising: a plurality of insulated conductors; a jacket extruded directly over the insulated conductors, the jacket having a cylindrical exterior with a plurality of spaced apart longitudinally extending grooves and a longitudinally extending recess formed thereon, the recess intersecting the cylindrical surface at two point in the range from 50 to 90 degrees apart, the recess having a base that is located a selected distance from the seam, the selected distance divided by a radius of the inner wall of the tubing being the range from 0.15 to 0.35; and a stainless steel tubing having a cylindrical inner wall and a longitudinally extending weld seam, the tubing having an outer diameter no greater than one inch, the tubing enclosing the jacket with the inner wall in frictional engagement with the jacket and the seam located adjacent the recess so as to avoid excessive heat to the jacket while the seam is being welded. 10. The cable of claim 9, wherein the exterior of the jacket has a plurality of longitudinally extending grooves formed thereon. 11. The cable of claim 9, wherein the outer diameter of the tubing is in the range from 0.75 inch to 1.00 inch.