Multicore power cable for immersion pumps - has tubular sheath of welded thin metal strip with tube dia. to wall thickness ratio between 18 and 35

摘要

In oil and natural gas bores are used drives operating in a depth exceeding 3000 m. The drives, preferably pumps are supplied with electric power from the surface. The cables for this purpose must withstand high pressure, as well as temperatures in the order of 120 deg.C. For this purpose the adjacent or bundled cores are protected each by an enclosed metal sheath, formed by at least one metal strip wound into a tube and held together by a long welding seam. The metal strip is thin, the ratio of the tube inner diameter to the wall thickness being 10 to 60, pref. 18 to 35. Pref. the sheath consists of two concentric metal strips, commonly corrugated and forming a multiple corrugated sleeve. At least the outer tube has a tinned surface. The outer tube may be of anti-corrosive material, i.e. a nickel-copper alloy. The corrugations of individual tubes may be parallel.