▎ 摘　　要

NOVELTY - The well monitoring system comprises a waveguide (5) having a graphene barrier (10), where the graphene barrier contains a material selected from the group consisting of graphene, graphene oxide and any combination. A signal generator generates a signal that travels through the waveguide. A signal detector detects a signal that travels through the waveguide. The waveguide comprises an optical fiber (20) and a polymer buffer (35). The waveguide is arranged underneath the polymer buffer. USE - Well monitoring system for applying protective graphene barrier to waveguides. ADVANTAGE - The cost and the waste of wellbore operations are reduced and the operational efficiency of wellbore operations is increased. The waveguides comprise a protective barrier that prevents or slows hydrogen diffusion into parts sensitive to hydrogen attack within the waveguides. The clear signals are important for obtaining accurate and sensitive readings and measurements from sensing operations. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a method for applying a graphene barrier to a waveguide; and (2) a method for using a waveguide in a well. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the waveguide with a portion cut away so that the interior of the waveguide is exposed. Waveguide (5) Graphene barrier (10) Optical fiber (20) Cladding (30) Polymer buffer (35)