Downhole fiber optic cable designed with improved strain response and designed for long life in the well

An optical fiber cable system for use in a first wellbore proximate to a subsurface formation, the optical fiber cable system comprising:

• an optical fiber cable comprising,
• one or more optical fibers configured in a state of axial compression at room temperature, wherein the one or more optical fibers are configured to remain in the state of axial compression during a thermal expansion of the optical fiber cable in the first wellbore;
• one or more coating layers comprised of a solid material and circumferentially disposed around the one or more optical fibers, wherein at least one of the one or more coating layers is configured to contact a cladding of the one or more optical fibers;
• and
• a metallic armor disposed around the one or more optical fibers and the one or more coating layers;
• and
• one or more sensors disposed in the first wellbore, wherein the one or more sensors and the optical fiber cable are configured to obtain measurements of cross-well strain between the first wellbore and a second wellbore.

A method for processing an optical fiber insert comprising one or more optical fibers to be used in a wellbore proximate to a subsurface formation, the method comprising:

• heating the optical fiber insert to a processing temperature;
• cooling the optical fiber insert to room temperature;
• and
• locking the optical fiber insert with a metallic armor to retain a state of compression in the one or more optical fibers.