# US 10,502,044 B2 · Multistage processing and inversion of corrosion detection tools > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,044 B2 - Document ID: US10502044B2 - Status: Granted - Kind: B2 - Application number: 15/570,549 - Filed: 2016-08-12 - Published: 2019-03-14 - Granted: 2019-12-10 - Earliest claimed: 2016-08-12 - Assignees: Halliburton Energy Services, Inc. - Applicants: Halliburton Energy Services, Inc. - Inventors: Ahmed Elsayed Fouda; Baris Guner; Luis Emilio San Martin - Web page: https://patentgrep.com/patent/US10502044B2 ## CPC - E21B 47/006: {Detection of corrosion or deposition of substances} - G01B 7/06: for measuring thickness {(measuring during the manufacture of coatings C23C14/54)} - E21B 47/002: by visual inspection - E21B 47/0025: {generating an image of the borehole wall using down-hole measurements, e.g. acoustic or electric} - E21B 47/08: Measuring diameters or related dimensions at the borehole - E21B 47/092: by detecting magnetic anomalies - E21B 47/113: using electrical indications; using light radiations - G01B 7/12: for measuring diameters - G01B 7/13: Internal diameters - G01V 3/18: specially adapted for well-logging - G01V 13/00: Manufacturing, calibrating, cleaning, or repairing instruments or devices covered by groups G01V1/00 – G01V11/00 - G01N 27/904: with two or more sensors - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - 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 Systems and methods for detection of downhole tubulars. A method may include disposing a corrosion detection tool in a plurality of concentric pipes, wherein the corrosion detection tool comprises a transmitter and a plurality of receivers; measuring a signal to provide a measured response; calibrating a log, wherein the calibrating comprises matching a nominal value of the measured response to a synthetic response to provide calibrated measurements; running a first inversion, wherein the first inversion comprises a first subset of the calibrated measurements that are used to compute a first estimate of properties of each of the concentric pipes; identifying pipes with an estimated thickness change from a nominal thickness to provide identified concentric pipes; selecting an innermost concentric pipe from the identified concentric pipes for computing an impulse response for deconvolution for improving vertical resolution of the measured response; applying deconvolution to a second subset of the calibrated measurements to provide calibrated and deconvolved measurements; and running a second inversion on the second subset of calibrated and deconvolved measurements, wherein the second inversion comprises at least one property of the plurality of concentric pipes. ## Claims ### Claim 1 A method comprising: disposing a corrosion detection tool in a plurality of concentric pipes, wherein the corrosion detection tool comprises a transmitter and a plurality of receivers; measuring a signal to provide a measured response; calibrating a log, wherein the calibrating comprises matching a nominal value of the measured response to a synthetic response to provide calibrated measurements; running a first inversion, wherein the first inversion comprises a first subset of the calibrated measurements that are used to compute a first estimate of properties of each of the concentric pipes; identifying pipes with an estimated thickness change from a nominal thickness to provide identified concentric pipes; selecting an innermost concentric pipe from the identified concentric pipes for computing an impulse response for deconvolution for improving vertical resolution of the measured response; applying deconvolution to a second subset of the calibrated measurements to provide calibrated and deconvolved measurements; and running a second inversion on the second subset of calibrated and deconvolved measurements, wherein the second inversion comprises at least one property of the plurality of concentric pipes. ### Claim 2 (depends on 1) The method of claim 1, wherein the properties of the first estimate comprise thickness, inner diameter, outer diameter, magnetic permeability, or electrical conductivity. ### Claim 3 (depends on 1) The method of claim 1, further comprising computing the synthetic response by modeling the concentric pipes with their nominal thicknesses. ### Claim 4 (depends on 1) The method of claim 1, wherein the first subset of the calibrated measurements comprise measurements from short-spaced receivers or measurements from all the receivers. ### Claim 5 (depends on 1) The method of claim 1, wherein the identifying comprises comparing a percentage change in estimated pipe thickness from the nominal thickness to a pre-defined threshold. ### Claim 6 (depends on 1) The method of claim 1, wherein the second subset of the calibrated measurements comprise measurements from long-spaced receivers or measurements from all the receivers. ### Claim 7 (depends on 1) The method of claim 1, wherein the at least one property of the plurality of concentric pipes is constrained. ### Claim 8 (depends on 1) The method of claim 1, wherein the at least one property of the plurality of concentric pipes is determined based on results of the first inversion. ### Claim 9 (depends on 1) The method of claim 1, further comprising displaying a result of the second inversion as a final inversion result. ### Claim 10 A method comprising: disposing a corrosion detection tool in a plurality of concentric pipes, wherein the corrosion detection tool comprises a transmitter and a plurality of receivers; stacking a number of log points in a buffer; running a first inversion, wherein the first inversion comprises a first subset of calibrated measurements that are used to compute a first estimate of properties of each of the concentric pipes; identifying one or more of the concentric pipes with an estimated thickness change from a nominal thickness to provide identified concentric pipes; selecting an innermost pipe from the identified concentric pipes with a thickness change for computing an impulse response for deconvolution; applying the deconvolution to a second subset of measurements; and running a second inversion, wherein the second inversion comprises at least one property of the plurality of concentric pipes, wherein the at least one property of the plurality of concentric pipes is constrained with a constraint. ### Claim 11 (depends on 10) The method of claim 10, wherein the at least one property of the plurality of concentric pipes is determined based on results of the first inversion. ### Claim 12 (depends on 10) The method of claim 10, further comprising displaying a result of the second inversion as a final inversion result. ### Claim 13 (depends on 10) The method of claim 10, wherein the constraint comprises a thickness of the concentric pipes identified to have nominal thickness from the first inversion. ### Claim 14 (depends on 10) The method of claim 10, wherein the constraint comprises a thickness of an innermost concentric pipe in addition to a thickness of the concentric pipes identified to have a nominal thickness from the first inversion. ### Claim 15 (depends on 10) The method of claim 10, wherein the constraint comprises a thickness of an innermost concentric pipe up to and including an innermost concentric pipe identified to have a thickness change from the first inversion. ### Claim 16 (depends on 10) The method of claim 10, wherein the at least one property of the plurality of concentric pipes of the second inversion comprises a magnetic permeability that is constrained to values computed in the first inversion. ### Claim 17 (depends on 10) The method of claim 10, wherein the constraint comprises results of the first inversion as an initial condition for the second inversion and an allowed thickness change within a fixed range only. ### Claim 18 (depends on 17) The method of claim 17, wherein the constraint further comprises a large weight to heavily penalize departure from an initial value. ### Claim 19 A system comprising: a corrosion detection tool, wherein the corrosion detection tool compromises a transmitter and a plurality of receivers; and an information handling system operable to: measure a signal to provide a measured response; calibrate a log by matching a nominal value of the measured response to a synthetic response; and run a first inversion, wherein the first inversion comprises a first subset of calibrated measurements that are used to compute a first estimate of properties of one or more pipes; select an innermost concentric pipe from the one or more pipes for computing an impulse response for deconvolution for improving vertical resolution of the measured response; apply deconvolution to a second subset of the calibrated measurements to provide calibrated and deconvolved measurements; and run a second inversion on the second subset of calibrated and deconvolved measurements, wherein the second inversion comprises at least one property of the plurality of concentric pipes. ### Claim 20 (depends on 19) The system of claim 19, wherein the information handling system is further operable to identify the one or more pipes with an estimated thickness change from a nominal thickness to provide identified one or more pipes.