Abstract: A system for providing information through a metal wall employs a device adapted to be arranged on one side of the metal wall and a magnetic-permeability element, provided at, near or connected to the device. The magnetic-permeability element is based on a material having a relative magnetic permeability of at least 2000. The disclosure also provides use of said system. The use may involve the step of optimizing the magnetic-permeability element using equivalent inductive mass (EIm). The system can for example be used to magnetically sense the location of a cable present on the outside of a wellbore tubular using a magnetic orienting tool that is located within the wellbore tubular.

Abstract: A metal wellbore tubular wall of a wellbore tubular, having a cable system arranged on an outside thereof, is to be perforated downhole. The cable system contains a fiber-optic cable, and a magnetic-permeability element with a relative magnetic permeability ?r,m of at least 2,000, such as an electrical steel, is configured along a length of the fiber-optic cable. The cable system is located by sensing the magnetic-permeability element through the metal wellbore tubular wall, using a magetic orienting tool which is being lowered into the wellbore tubular. subsequently, the metal wellbore tubular wall is perforated in a direction away from the cable system.

Abstract: A system for providing information through a metal wall employs a device adapted to be arranged on one side of the metal wall and a magnetic-permeability element, provided at, near or connected to the device. The magnetic-permeability element is based on a material having a relative magnetic permeability of at least 2000. The disclosure also provides use of said system. The use may involve the step of optimizing the magnetic-permeability element using equivalent inductive mass (EIm). The system can for example be used to magnetically sense the location of a cable present on the outside of a wellbore tubular using a magetic orienting tool that is located within the wellbore tubular.

Abstract: A system for providing information through a metal wall employs a device (10), such as a fiber optic cable, adapted to be arranged on one side of the metal wall (20) and a magnetic-permeability element (11), provided at, near or connected to the device. The magnetic-permeability element is based on a material having a relative magnetic permeability of at least 2000. The disclosure also provides use of said system. The use may involve the step of optimizing the magnetic-permeability element using equivalent inductive mass (Elm). The system can for example be used to magnetically sense the location of a cable (10) present on the outside of a wellbore tubular (20) using a magnetic orienting tool that is located within the wellbore tubular.