UN PROCEDIMIENTO PARA CALENTAR UN INTERVALO APRECIABLEMENTE LARGO DE FORMACIONES TERRESTRES SUBTERRANEAS Y CALENTADOR DE POZO CORRESPONDIENTE.

摘要

A long interval of subterranean earth formation is heated at a high temp. which can be sustained for a long time by electrical heater arranged to have at least one heating element within the interval to be heated, the heating element(s) consisting of (a) an electrically conductive core or conductor which has a low resistance at a high temp.; (b) a core-surrounding insulating material having properties of electrical resistance, compressive strength and heat conductivity which are high at a high temp. and (c) a core and insulation-surrounding metal sheath having properties of tensile strength, creep resistance and softening resistance which are relatively high at high temp.