# US 10,371,502 B2 · Systems and devices for sensing corrosion and deposition for oil and gas applications > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,502 B2 - Document ID: US10371502B2 - Status: Granted - Kind: B2 - Application number: 15/387,110 - Filed: 2016-12-21 - Published: 2017-04-13 - Granted: 2019-08-06 - Earliest claimed: 2014-06-30 - Assignees: Baker Highes, A Ge Company, LLC - Applicants: Baker Hughes, a GE Company, LLC - Inventors: Anusha Chilukuri; Othon R. Monteiro - Web page: https://patentgrep.com/patent/US10371502B2 ## CPC - G01B 11/0675: {using interferometry} - E21B 47/006: {Detection of corrosion or deposition of substances} - E21B 47/135: using light waves, e.g. infrared or ultraviolet waves - G01B 11/14: for measuring distance or clearance between spaced objects or spaced apertures (G01B11/26 takes precedence; rangefinders G01C3/00) - G01N 17/04: Corrosion probes - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Sensing systems include a tube defining a Fabry-Perot cavity and an optical fiber including a distal end disposed within the Fabry-Perot cavity and a proximal end. A corrodible material caps the Fabry-Perot cavity. Devices for sensing corrosion of downhole equipment include an optical fiber with a corrodible material disposed over a distal end of the optical fiber. Systems for sensing a condition in equipment include an optical fiber with a fiber Bragg grating proximate a distal end thereof and a mass of sensor material coupled to the distal end of the optical fiber. The mass of sensor material is suspended from above the fiber Bragg grating. Other systems for sensing a condition in a wellbore include an optical fiber and a plurality of fiber Bragg gratings along a length thereof. A plurality of sensor materials are coupled to the optical fiber and surround respective fiber Bragg gratings. ## Claims ### Claim 1 A wellbore sensing system, comprising: a tube defining a Fabry-Perot cavity; an optical fiber comprising a distal end disposed within the Fabry-Perot cavity and a proximal end opposite the distal end; a material capping the Fabry-Perot cavity; another tube defining another Fabry-Perot cavity; at least one other optical fiber, a distal end of the at least one other optical fiber disposed within the another Fabry-Perot cavity; an inert material capping the another Fabry-Perot cavity; and an analysis module operatively coupled to the proximal end of the optical fiber, the analysis module configured to sense and analyze a difference of a light signal resulting from a change in a distance between the material and the distal end of the optical fiber due to a change in thickness of the material. ### Claim 2 (depends on 1) The wellbore sensing system of claim 1, wherein the tube is positioned proximate a downhole component within a wellbore. ### Claim 3 (depends on 1) The wellbore sensing system of claim 1, wherein the distal end of the optical fiber is mounted to an electrical submersible pump. ### Claim 4 (depends on 1) The wellbore sensing system of claim 1, wherein the material is selected from the group consisting of aluminum, titanium, a carbon steel, a tool steel, a stainless steel, and a corrosion-resistant alloy. ### Claim 5 (depends on 1) The wellbore sensing system of claim 1, wherein the inert material capping the another Fabry-Perot cavity comprises one or more of a ceramic material, a diamond-like carbon material, an oxide material, a sapphire material, an alumina material, a silicon carbide material, a silicon material, and a metallic material coated with the inert material. ### Claim 6 (depends on 1) The wellbore sensing system of claim 1, wherein the analysis module further comprises a light source coupled to the optical fiber and the at least one other optical fiber, an interferometer coupled to a proximal end of the optical fiber and the at least one other optical fiber, and an output configured to provide a signal corresponding to a corrosion rate of the material. ### Claim 7 (depends on 1) The wellbore sensing system of claim 1, further comprising at least one additional optical fiber comprising a distal end disposed within the Fabry-Perot cavity, wherein a separate corrodible material is disposed over a respective distal end of each of the optical fiber and the at least one additional optical fiber, wherein each of the separate corrodible materials comprises a different thickness from other separate corrodible materials. ### Claim 8 (depends on 1) The wellbore sensing system of claim 1, further comprising: a mask with an aperture therethrough, the mask covering the material, the mask and aperture configured to selectively expose respective regions of the material corresponding to the optical fiber and a at least one additional optical fiber. ### Claim 9 (depends on 1) The wellbore sensing system of claim 1, further comprising additional optical fibers comprising respective distal ends disposed within the Fabry-Perot cavity and respective proximal ends opposite the distal ends, wherein the analysis module is operatively coupled to the proximal ends of the additional optical fibers. ### Claim 10 (depends on 1) The wellbore sensing system of claim 1, wherein the Fabry-Perot cavity is filled with a liquid or a gas. ### Claim 11 A wellbore sensing system, comprising: a tube defining a Fabry-Perot cavity; an optical fiber comprising a distal end disposed within the Fabry-Perot cavity and a proximal end opposite the distal end; a material capping the Fabry-Perot cavity; an analysis module operatively coupled to the proximal end of the optical fiber, the analysis module configured to sense and analyze a difference of a light signal resulting from a change in a distance between the material and the distal end of the optical fiber due to a change in thickness of the material; and additional optical fibers comprising respective distal ends disposed within the Fabry-Perot cavity and respective proximal ends opposite the distal ends, wherein the analysis module is operatively coupled to the proximal ends of the additional optical fibers. ### Claim 12 A wellbore sensing system, comprising: a tube defining a Fabry-Perot cavity; an optical fiber comprising a distal end disposed within the Fabry-Perot cavity and a proximal end opposite the distal end; a material capping the Fabry-Perot cavity; at least one additional optical fiber, the at least one additional optical fiber comprising a distal end disposed within the Fabry-Perot cavity, wherein a separate material is disposed over a respective distal end of each of the optical fiber and the at least one additional optical fiber, wherein each of the separate materials comprises a different thickness from other separate materials; and an analysis module operatively coupled to the proximal end of the optical fiber, the analysis module configured to sense and analyze a difference of a light signal resulting from a change in a distance between the material and the distal end of the optical fiber due to a change in thickness of the material.