| 摘要 |
<p>A cable used for feeding electric power to pumps for lifting crude oil in an oil well. The cable is the one in which an insulation layer, a resin sheath and a metal sheath are built up successively on a conductor, and a protective layer comprising a heat-proof tape wound on at least one of the insulation layer and the resin sheath is formed. The generation of holes in a cable which are caused by the pressure change occurred when the cable is drawn up after immersing it into the oil well and the breakdown of insulation layers can be prevented by the protective layer.</p> |
